https://en.lntwww.de/index.php?title=Modulation_Methods/Double-Sideband_Amplitude_Modulation&feed=atom&action=history
Modulation Methods/Double-Sideband Amplitude Modulation - Revision history
2024-03-28T18:17:26Z
Revision history for this page on the wiki
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https://en.lntwww.de/index.php?title=Modulation_Methods/Double-Sideband_Amplitude_Modulation&diff=51873&oldid=prev
Hwang at 12:42, 18 January 2023
2023-01-18T12:42:38Z
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 12:42, 18 January 2023</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l124" >Line 124:</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The Fourier series representation of the periodic rectangular signal&nbsp;$z_{\rm R}(t)$&nbsp; is:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The Fourier series representation of the periodic rectangular signal&nbsp;$z_{\rm R}(t)$&nbsp; is:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$z_{\rm R}(t) = \frac{4}{\pi} \cdot \cos(\omega_{\rm T}\cdot t)-\frac{4}{3\pi} \cdot \cos(3\omega_{\rm T}\cdot t) +\frac{4}{5\pi} \cdot \cos(5\omega_{\rm T}\cdot t)- \text{ ...}$$</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$z_{\rm R}(t) = \frac{4}{\pi} \cdot \cos(\omega_{\rm T}\cdot t)-\frac{4}{3\pi} \cdot \cos(3\omega_{\rm T}\cdot t) +\frac{4}{5\pi} \cdot \cos(5\omega_{\rm T}\cdot t)- \text{ ...}$$</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*The associated spectral function consists of Dirac lines at &nbsp;$±f_{\rm T}, ±3f_{\rm T}, ±5f_{\rm T}$, etc.&nbsp; Convolution with &nbsp;$Q(f)$&nbsp; leads to the spectrum <br>(the subscript stands for "ring modulator"):</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*The associated spectral function consists of Dirac <ins class="diffchange diffchange-inline">delta </ins>lines at &nbsp;$±f_{\rm T}, ±3f_{\rm T}, ±5f_{\rm T}$, etc.&nbsp; Convolution with &nbsp;$Q(f)$&nbsp; leads to the spectrum <br>(the subscript stands for "ring modulator"):</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$S_{\rm RM}(f) = \frac{2}{\pi} \cdot Q (f \pm f_{\rm T})-\frac{2}{3\pi} \cdot Q (f \pm 3f_{\rm</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$S_{\rm RM}(f) = \frac{2}{\pi} \cdot Q (f \pm f_{\rm T})-\frac{2}{3\pi} \cdot Q (f \pm 3f_{\rm</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> T})+\frac{2}{5\pi} \cdot Q (f \pm 5f_{\rm T}) -\text{ ...} \hspace{0.05cm}$$</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> T})+\frac{2}{5\pi} \cdot Q (f \pm 5f_{\rm T}) -\text{ ...} \hspace{0.05cm}$$</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l154" >Line 154:</td>
<td colspan="2" class="diff-lineno">Line 154:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This result,&nbsp; which would also have been arrived at via convolution,&nbsp; states:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This result,&nbsp; which would also have been arrived at via convolution,&nbsp; states:</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>#The spectrum consists of four Dirac lines at frequencies &nbsp;$±(f_{\rm T} + f_{\rm N})$&nbsp; and &nbsp;$±(f_{\rm T} - f_{\rm N})$.&nbsp; </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>#The spectrum consists of four Dirac <ins class="diffchange diffchange-inline">delta </ins>lines at frequencies &nbsp;$±(f_{\rm T} + f_{\rm N})$&nbsp; and &nbsp;$±(f_{\rm T} - f_{\rm N})$.&nbsp; </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#In both bracket expressions, the first Dirac delta function indicates the one for positive frequencies. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#In both bracket expressions, the first Dirac delta function indicates the one for positive frequencies. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#The weights of all Dirac delta functions are equal and each is &nbsp;$A_{\rm N}/4$.&nbsp; </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#The weights of all Dirac delta functions are equal and each is &nbsp;$A_{\rm N}/4$.&nbsp; </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#The sum of these weights &nbsp; - that is, the integral over&nbsp; $S(f)$ - &nbsp; is equal to the signal value&nbsp; $s(t = 0) = A_{\rm N}$. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#The sum of these weights &nbsp; - that is, the integral over&nbsp; $S(f)$ - &nbsp; is equal to the signal value&nbsp; $s(t = 0) = A_{\rm N}$. </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>#The Dirac lines remain for &nbsp;$ϕ_{\rm T} ≠ 0$&nbsp; and/or &nbsp;$ϕ_{\rm N} ≠ 0$&nbsp; at the same frequencies.&nbsp; However, complex rotation factors must then be added to the weights &nbsp;$A_{\rm N}/4$&nbsp;.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>#The Dirac <ins class="diffchange diffchange-inline">delta </ins>lines remain for &nbsp;$ϕ_{\rm T} ≠ 0$&nbsp; and/or &nbsp;$ϕ_{\rm N} ≠ 0$&nbsp; at the same frequencies.&nbsp; However, complex rotation factors must then be added to the weights &nbsp;$A_{\rm N}/4$&nbsp;.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{GraueBox|TEXT=</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{GraueBox|TEXT=</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>$\text{Example 3:}$&nbsp; The following diagram shows the spectral functions &nbsp;$S(f)$&nbsp; for different values of &nbsp;$ϕ_{\rm T}$&nbsp; and &nbsp;$ϕ_{\rm N}$,&nbsp; respectively.&nbsp; The other parameters are assumed to be &nbsp;$f_{\rm T} = 50\text{ kHz}$, &nbsp;$f_{\rm N} = 10\text{ kHz}$&nbsp; and &nbsp;$A_{\rm N} = 4\text{ V}$.&nbsp; Thus,&nbsp; the magnitudes of all Dirac lines are&nbsp;$A_{\rm N}/4 = 1\text{ V}$. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>$\text{Example 3:}$&nbsp; The following diagram shows the spectral functions &nbsp;$S(f)$&nbsp; for different values of &nbsp;$ϕ_{\rm T}$&nbsp; and &nbsp;$ϕ_{\rm N}$,&nbsp; respectively.&nbsp; The other parameters are assumed to be &nbsp;$f_{\rm T} = 50\text{ kHz}$, &nbsp;$f_{\rm N} = 10\text{ kHz}$&nbsp; and &nbsp;$A_{\rm N} = 4\text{ V}$.&nbsp; Thus,&nbsp; the magnitudes of all Dirac <ins class="diffchange diffchange-inline">delta </ins>lines are&nbsp;$A_{\rm N}/4 = 1\text{ V}$. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:EN_Mod_T_2_1_S4.png|right|frame|Typical spectra for DSB-AM]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:EN_Mod_T_2_1_S4.png|right|frame|Typical spectra for DSB-AM]]</div></td></tr>
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Hwang
https://en.lntwww.de/index.php?title=Modulation_Methods/Double-Sideband_Amplitude_Modulation&diff=51775&oldid=prev
Guenter at 17:35, 12 January 2023
2023-01-12T17:35:48Z
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<table class="diff diff-contentalign-left" data-mw="interface">
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 17:35, 12 January 2023</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l8" >Line 8:</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== # OVERVIEW OF THE SECOND MAIN CHAPTER # ==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== # OVERVIEW OF THE SECOND MAIN CHAPTER # ==</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>After some general explanations of modulation and demodulation,&nbsp; now a detailed description of&nbsp; <del class="diffchange diffchange-inline">"</del>amplitude modulation<del class="diffchange diffchange-inline">"</del>&nbsp; and the associated&nbsp; <del class="diffchange diffchange-inline">"</del>demodulators<del class="diffchange diffchange-inline">"</del>.&nbsp;This chapter deals in detail with:</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>After some general explanations of modulation and demodulation,&nbsp; now a detailed description of&nbsp; <ins class="diffchange diffchange-inline">'''&raquo;</ins>amplitude modulation<ins class="diffchange diffchange-inline">&laquo;'''</ins>&nbsp; and the associated&nbsp; <ins class="diffchange diffchange-inline">'''&raquo;</ins>demodulators<ins class="diffchange diffchange-inline">&laquo;'''</ins>.&nbsp;</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*the description and realization of&nbsp; <del class="diffchange diffchange-inline">"</del>double-sideband amplitude modulation<del class="diffchange diffchange-inline">"</del>&nbsp; $\text{(DSB–AM)}$&nbsp; in frequency and time domain,</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*the characteristics of a&nbsp; <del class="diffchange diffchange-inline">"</del>synchronous demodulator<del class="diffchange diffchange-inline">"</del>&nbsp; and the possible applications of an&nbsp; <del class="diffchange diffchange-inline">"</del>envelope demodulator<del class="diffchange diffchange-inline">"</del>,</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>This chapter deals in detail with:</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*the similarities/differences of&nbsp; <del class="diffchange diffchange-inline">"</del>single-sideband modulation<del class="diffchange diffchange-inline">"</del>&nbsp; $\text{(SSB–AM)}$&nbsp; compared to DSB-AM and &nbsp; <del class="diffchange diffchange-inline">"</del>modified AM methods<del class="diffchange diffchange-inline">"</del>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*the description and realization of&nbsp; <ins class="diffchange diffchange-inline">&raquo;</ins>double-sideband amplitude modulation<ins class="diffchange diffchange-inline">&laquo;</ins>&nbsp; $\text{(DSB–AM)}$&nbsp; in frequency and time domain,</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*the characteristics of a&nbsp; <ins class="diffchange diffchange-inline">&raquo;</ins>synchronous demodulator<ins class="diffchange diffchange-inline">&laquo;</ins>&nbsp; and the possible applications of an&nbsp; <ins class="diffchange diffchange-inline">&raquo;</ins>envelope demodulator<ins class="diffchange diffchange-inline">&laquo;</ins>,</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*the similarities/differences of&nbsp; <ins class="diffchange diffchange-inline">&raquo;</ins>single-sideband modulation<ins class="diffchange diffchange-inline">&raquo;</ins>&nbsp; $\text{(SSB–AM)}$&nbsp; compared to DSB-AM and&nbsp; <ins class="diffchange diffchange-inline">&raquo;</ins>modified AM methods<ins class="diffchange diffchange-inline">&raquo;</ins>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l17" >Line 17:</td>
<td colspan="2" class="diff-lineno">Line 21:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>We consider the following problem:&nbsp; a source signal&nbsp;$q(t)$,&nbsp; whose spectrum &nbsp;$Q(f)$&nbsp; is bandlimited to the range &nbsp;$\pm B_{\rm NF}$&nbsp; (subscript&nbsp; "NF"&nbsp; from German "Niederfrequenz" &nbsp; ⇒ &nbsp; low frequency),&nbsp;</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>We consider the following problem:&nbsp; a source signal&nbsp;$q(t)$,&nbsp; whose spectrum &nbsp;$Q(f)$&nbsp; is bandlimited to the range &nbsp;$\pm B_{\rm NF}$&nbsp; (subscript&nbsp; "NF"&nbsp; from German "Niederfrequenz" &nbsp; ⇒ &nbsp; low frequency),&nbsp;</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* is to be shifted to a higher frequency range where the channel frequency response&nbsp; $H_{\rm K}(f)$&nbsp; has favorable characteristics,&nbsp; </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>* is to be shifted to a higher frequency range where the channel frequency response&nbsp; $H_{\rm K}(f)$&nbsp; has favorable characteristics,&nbsp;</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline"> </ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*using a harmonic oscillation of frequency &nbsp;$f_{\rm T}$, which we will refer to as the carrier signal&nbsp; $z(t)$. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*using a harmonic oscillation of frequency &nbsp;$f_{\rm T}$, which we will refer to as the carrier signal&nbsp; $z(t)$. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l25" >Line 25:</td>
<td colspan="2" class="diff-lineno">Line 30:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:P_ID974__Mod_T_2_1_S1a_neu.png |right|frame|Representation of amplitude modulation in the frequency domain]] </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:P_ID974__Mod_T_2_1_S1a_neu.png |right|frame|Representation of amplitude modulation in the frequency domain]] </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The spectrum &nbsp;$Q(f)$&nbsp; drawn here is schematic.&nbsp; It states that only spectral components in the range &nbsp;$|f| ≤ B_{\rm NF}$&nbsp; are included in &nbsp;$q(t)$.&nbsp; $Q(f)$&nbsp; could also be a line spectrum. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The spectrum &nbsp;$Q(f)$&nbsp; drawn here is schematic.&nbsp; It states that only spectral components in the range &nbsp;$|f| ≤ B_{\rm NF}$&nbsp; are included in &nbsp;$q(t)$.&nbsp; $Q(f)$&nbsp; could also be a line spectrum. </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*Let the channel be ideal in a bandwidth range &nbsp;$B_{\rm K}$&nbsp; around frequency&nbsp; $f_{\rm M}$,&nbsp; that is, let &nbsp;$H_{\rm K}(f) = 1$&nbsp; for &nbsp;$|f - f_{\rm M}| ≤ B_{\rm K}/2.$&nbsp; Impairments by noise are ignored for now. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*Let the channel be ideal in a bandwidth range &nbsp;$B_{\rm K}$&nbsp; around frequency&nbsp; $f_{\rm M}$,&nbsp; that is, let &nbsp;$H_{\rm K}(f) = 1$&nbsp; for &nbsp;$|f - f_{\rm M}| ≤ B_{\rm K}/2.$&nbsp; Impairments by noise are ignored for now.</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline"> </ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Let the carrier signal be cosine &nbsp; $($phase &nbsp;$ϕ_{\rm T} = 0)$&nbsp; and have amplitude&nbsp; $A_{\rm T} = 1$&nbsp; (without a unit).&nbsp; Let the carrier frequency &nbsp;$f_{\rm T}$&nbsp; be equal to the center frequency of the transmission band. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Let the carrier signal be cosine &nbsp; $($phase &nbsp;$ϕ_{\rm T} = 0)$&nbsp; and have amplitude&nbsp; $A_{\rm T} = 1$&nbsp; (without a unit).&nbsp; Let the carrier frequency &nbsp;$f_{\rm T}$&nbsp; be equal to the center frequency of the transmission band. </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Thus,&nbsp; the spectrum of the carrier signal &nbsp;$z(t) = \cos(ω_{\rm T} · t)$&nbsp; is <br>(plotted in green in the graph): </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Thus,&nbsp; the spectrum of the carrier signal &nbsp;$z(t) = \cos(ω_{\rm T} · t)$&nbsp; is <br>(plotted in green in the graph): </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$Z(f) = {1}/{2} \cdot \delta (f + f_{\rm T})+{1}/{2} \cdot \delta (f - f_{\rm T})\hspace{0.05cm}.$$</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$Z(f) = {1}/{2} \cdot \delta (f + f_{\rm T})+{1}/{2} \cdot \delta (f - f_{\rm T})\hspace{0.05cm}.$$</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l41" >Line 41:</td>
<td colspan="2" class="diff-lineno">Line 49:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The diagram displays the result.&nbsp; One can identify the following characteristics: </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The diagram displays the result.&nbsp; One can identify the following characteristics: </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:EN_Mod_T_2_1_S1b.png|right|frame|Spectrum of double-sideband amplitude modulation without carrier; <br>other name:&nbsp; "double-sideband amplitude modulation with carrier suppression"]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:EN_Mod_T_2_1_S1b.png|right|frame|Spectrum of double-sideband amplitude modulation without carrier; <br>other name:&nbsp; "double-sideband amplitude modulation with carrier suppression"]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*Due to the system-theoretic approach with positive and negative frequencies,&nbsp;$S(f)$&nbsp; is composed of two parts around &nbsp;$\pm f_{\rm T}$,&nbsp; each of which have the same shape as &nbsp;$Q(f)$. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*Due to the system-theoretic approach with positive and negative frequencies,&nbsp;$S(f)$&nbsp; is composed of two parts around &nbsp;$\pm f_{\rm T}$,&nbsp; each of which have the same shape as &nbsp;$Q(f)$.</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*The factor &nbsp;$1/2$&nbsp; results from the carrier amplitude &nbsp;$A_{\rm T} = 1$.&nbsp; Thus,&nbsp; $s(t = 0) = q(t = 0)$&nbsp; and the integrals over their spectral functions&nbsp; $S(f)$&nbsp; and &nbsp;$Q(f)$&nbsp; must also be equal. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline"> </ins></div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*The channel bandwidth &nbsp;$B_{\rm K}$&nbsp; must be at least twice the signal bandwidth &nbsp;$B_{\rm NF}$,&nbsp; which gives the name&nbsp; <br>&raquo;'''Double-Sideband Amplitude Modulation'''&laquo;&nbsp; $\text{(DSB–AM)}$. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*The factor &nbsp;$1/2$&nbsp; results from the carrier amplitude &nbsp;$A_{\rm T} = 1$.&nbsp; Thus,&nbsp; $s(t = 0) = q(t = 0)$&nbsp; and the integrals over their spectral functions&nbsp; $S(f)$&nbsp; and &nbsp;$Q(f)$&nbsp; must also be equal.</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline"> </ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*The channel bandwidth &nbsp;$B_{\rm K}$&nbsp; must be at least twice the signal bandwidth &nbsp;$B_{\rm NF}$,&nbsp; which gives the name&nbsp; <br>&raquo;'''Double-Sideband Amplitude Modulation'''&laquo;&nbsp; $\text{(DSB–AM)}$.</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline"> </ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*It should be noted that&nbsp;$B_{\rm NF}$ and $B_{\rm K}$&nbsp; are absolute and &nbsp;[[Signal_Representation/Fourier_Transform_Theorems#Reciprocity_Theorem_of_time_duration_and_bandwidth|$\text{non-equivalent bandwidths}$]].&nbsp; The latter are defined over rectangles of equal area and are denoted in our tutorial by&nbsp; $Δf_q$&nbsp; and&nbsp; $Δf_{\rm K}$,&nbsp; resp. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*It should be noted that&nbsp;$B_{\rm NF}$ and $B_{\rm K}$&nbsp; are absolute and &nbsp;[[Signal_Representation/Fourier_Transform_Theorems#Reciprocity_Theorem_of_time_duration_and_bandwidth|$\text{non-equivalent bandwidths}$]].&nbsp; The latter are defined over rectangles of equal area and are denoted in our tutorial by&nbsp; $Δf_q$&nbsp; and&nbsp; $Δf_{\rm K}$,&nbsp; resp. </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*The spectral function &nbsp;$S(f)$&nbsp; does not include any Dirac-lines at the carrier frequency &nbsp;$(\pm f_{\rm T})$.&nbsp; Therefore, this method is also referred to as&nbsp; "DSB-AM '''without carrier'''". </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*The spectral function &nbsp;$S(f)$&nbsp; does not include any Dirac-lines at the carrier frequency &nbsp;$(\pm f_{\rm T})$.&nbsp; Therefore, this method is also referred to as&nbsp; "DSB-AM '''without carrier'''".</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline"> </ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The frequency components </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The frequency components </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:*above the carrier frequency &nbsp;$f_{\rm T}$&nbsp; are called the&nbsp; "upper sideband"&nbsp; $\rm (USB)$, </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:*above the carrier frequency &nbsp;$f_{\rm T}$&nbsp; are called the&nbsp; "upper sideband"&nbsp; $\rm (USB)$, </div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l63" >Line 63:</td>
<td colspan="2" class="diff-lineno">Line 76:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>According to this equation, two models can be given for double-sideband amplitude modulation.&nbsp; These are to be interpreted as follows: </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>According to this equation, two models can be given for double-sideband amplitude modulation.&nbsp; These are to be interpreted as follows: </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*The upper model directly describes the relationship given above,&nbsp; where the carrier &nbsp;$z(t) = \cos(ω_{\rm T}t + ϕ_{\rm T})$&nbsp; is applied without a unit. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*The upper model directly describes the relationship given above,&nbsp; where the carrier &nbsp;$z(t) = \cos(ω_{\rm T}t + ϕ_{\rm T})$&nbsp; is applied without a unit.</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*The lower model is more in line with the physical condition&nbsp; "each signal also has a unit".&nbsp; If &nbsp;$q(t)$&nbsp; and &nbsp;$z(t)$&nbsp; are voltages,&nbsp; the model still needs to provide a scaling with the modulator constant &nbsp;$K_{\rm AM}$&nbsp; with unit&nbsp; &nbsp;$\rm 1/V$,&nbsp; so that the output signal &nbsp;$s(t)$&nbsp; also represents a voltage waveform. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline"> </ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*The lower model is more in line with the physical condition&nbsp; "each signal also has a unit".&nbsp; If &nbsp;$q(t)$&nbsp; and &nbsp;$z(t)$&nbsp; are voltages,&nbsp; the model still needs to provide a scaling with the modulator constant &nbsp;$K_{\rm AM}$&nbsp; with unit&nbsp; &nbsp;$\rm 1/V$,&nbsp; so that the output signal &nbsp;$s(t)$&nbsp; also represents a voltage waveform.</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline"> </ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*If we set &nbsp;$K_{\rm AM} = 1/A_{\rm T}$,&nbsp; both models are the same.&nbsp; In the following,&nbsp; we will always assume the lower, simpler model.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*If we set &nbsp;$K_{\rm AM} = 1/A_{\rm T}$,&nbsp; both models are the same.&nbsp; In the following,&nbsp; we will always assume the lower, simpler model.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br clear=all></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br clear=all></div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l82" >Line 82:</td>
<td colspan="2" class="diff-lineno">Line 97:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:P_ID978__Mod_T_2_1_S3a_neu.png|right|frame|Ring modulator to realize DSB–AM without carrier]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:P_ID978__Mod_T_2_1_S3a_neu.png|right|frame|Ring modulator to realize DSB–AM without carrier]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Let the amplitude of the harmonic carrier oscillation&nbsp; $z(t)$&nbsp; be much larger than the maximum value &nbsp;$q_{\rm max}$&nbsp; of the source signal&nbsp; $q(t)$.&nbsp; Thus,&nbsp; all diodes are operated as switches.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Let the amplitude of the harmonic carrier oscillation&nbsp; $z(t)$&nbsp; be much larger than the maximum value &nbsp;$q_{\rm max}$&nbsp; of the source signal&nbsp; $q(t)$.&nbsp; Thus,&nbsp; all diodes are operated as switches.</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*When the half-wave of the carrier is positive &nbsp;$(z(t) > 0)$&nbsp; the two magenta diodes conduct while the light green ones block. Thus, without considering losses,&nbsp; it holds&nbsp; $s(t) = q(t)$. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*When the half-wave of the carrier is positive &nbsp;$(z(t) > 0)$&nbsp; the two magenta diodes conduct while the light green ones block. Thus, without considering losses,&nbsp; it holds&nbsp; $s(t) = q(t)$. </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*For a negative half-wave,&nbsp; the light green diodes conduct and the diodes in the longitudinal branches block.&nbsp; As can be seen on the right,&nbsp; $s(t) = \ – q(t)$&nbsp; holds for this lower switch position. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*For a negative half-wave,&nbsp; the light green diodes conduct and the diodes in the longitudinal branches block.&nbsp; As can be seen on the right,&nbsp; $s(t) = \ – q(t)$&nbsp; holds for this lower switch position. </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Due to the operation of this switch,&nbsp; the harmonic oscillation&nbsp; $z(t)$&nbsp; can also be replaced by a periodic&nbsp; (rectangular)&nbsp; square wave signal with identical period duration: </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Due to the operation of this switch,&nbsp; the harmonic oscillation&nbsp; $z(t)$&nbsp; can also be replaced by a periodic&nbsp; (rectangular)&nbsp; square wave signal with identical period duration: </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$z_{\rm R}(t) = \left\{ \begin{array}{c} +1 \\ -1 \\ \end{array} \right.\quad \begin{array}{*{10}c} {\rm{for}} \\ {\rm{for}} \\ \end{array}\begin{array}{*{20}c} {z(t) >0,} \\ {z(t) <0.} \\ \end{array}$$</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$z_{\rm R}(t) = \left\{ \begin{array}{c} +1 \\ -1 \\ \end{array} \right.\quad \begin{array}{*{10}c} {\rm{for}} \\ {\rm{for}} \\ \end{array}\begin{array}{*{20}c} {z(t) >0,} \\ {z(t) <0.} \\ \end{array}$$</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*The modulated signal&nbsp; $s(t)$&nbsp; is then obtained as the product of the source signal &nbsp;$q(t)$&nbsp; and this <del class="diffchange diffchange-inline">square wave '''KORREKTUR: </del>rectangular<del class="diffchange diffchange-inline">''' </del>signal &nbsp;$z_{\rm R}(t)$,&nbsp; whereas in ideal DSB-AM one multiplies&nbsp;$q(t)$&nbsp; by a cosine signal.&nbsp; The carrier &nbsp;$z(t)$&nbsp; is not itself included in the signal&nbsp;$s(t)$.&nbsp; Since this is supplied via the center taps of the transformers, the induced voltages cancel out &nbsp; &rArr; &nbsp; &raquo;'''DSB-AM without carrier'''&laquo;. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*The modulated signal&nbsp; $s(t)$&nbsp; is then obtained as the product of the source signal &nbsp;$q(t)$&nbsp; and this <ins class="diffchange diffchange-inline"> </ins>rectangular signal &nbsp;$z_{\rm R}(t)$,&nbsp; whereas in ideal DSB-AM one multiplies&nbsp;$q(t)$&nbsp; by a cosine signal.&nbsp; The carrier &nbsp;$z(t)$&nbsp; is not itself included in the signal&nbsp;$s(t)$.&nbsp; Since this is supplied via the center taps of the transformers, the induced voltages cancel out &nbsp; &rArr; &nbsp; &raquo;'''DSB-AM without carrier'''&laquo;. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l118" >Line 118:</td>
<td colspan="2" class="diff-lineno">Line 137:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Please note: &nbsp; Since we are describing modulation processes,&nbsp; the phase term is used with a plus sign in the above equations. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Please note: &nbsp; Since we are describing modulation processes,&nbsp; the phase term is used with a plus sign in the above equations. </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*Thus, &nbsp;$ϕ_{\rm N} = - 90^\circ$&nbsp; represents a sinusoidal input signal &nbsp;$q(t)$&nbsp; and&nbsp; $ϕ_{\rm T} = - 90^\circ$&nbsp; denotes a sinusoidal carrier signal&nbsp; $z(t)$. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*Thus, &nbsp;$ϕ_{\rm N} = - 90^\circ$&nbsp; represents a sinusoidal input signal &nbsp;$q(t)$&nbsp; and&nbsp; $ϕ_{\rm T} = - 90^\circ$&nbsp; denotes a sinusoidal carrier signal&nbsp; $z(t)$.</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline"> </ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Therefore,&nbsp; the equation for the modulated signal is:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Therefore,&nbsp; the equation for the modulated signal is:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$s(t) = q(t) \cdot z(t) = A_{\rm N} \cdot \cos(\omega_{\rm N} t + \phi_{\rm</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$s(t) = q(t) \cdot z(t) = A_{\rm N} \cdot \cos(\omega_{\rm N} t + \phi_{\rm</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l134" >Line 134:</td>
<td colspan="2" class="diff-lineno">Line 154:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This result,&nbsp; which would also have been arrived at via convolution,&nbsp; states:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This result,&nbsp; which would also have been arrived at via convolution,&nbsp; states:</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">*</del>The spectrum consists of four Dirac lines at frequencies &nbsp;$±(f_{\rm T} + f_{\rm N})$&nbsp; and &nbsp;$±(f_{\rm T} - f_{\rm N})$.&nbsp; </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">#</ins>The spectrum consists of four Dirac lines at frequencies &nbsp;$±(f_{\rm T} + f_{\rm N})$&nbsp; and &nbsp;$±(f_{\rm T} - f_{\rm N})$.&nbsp; </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">*</del>In both bracket expressions, the first Dirac delta function indicates the one for positive frequencies. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">#</ins>In both bracket expressions, the first Dirac delta function indicates the one for positive frequencies. </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">*</del>The weights of all Dirac delta functions are equal and each is &nbsp;$A_{\rm N}/4$.&nbsp; </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">#</ins>The weights of all Dirac delta functions are equal and each is &nbsp;$A_{\rm N}/4$.&nbsp; </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">*</del>The sum of these weights &nbsp; - that is, the integral over&nbsp; $S(f)$ - &nbsp; is equal to the signal value&nbsp; $s(t = 0) = A_{\rm N}$. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">#</ins>The sum of these weights &nbsp; - that is, the integral over&nbsp; $S(f)$ - &nbsp; is equal to the signal value&nbsp; $s(t = 0) = A_{\rm N}$. </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">*</del>The Dirac lines remain for &nbsp;$ϕ_{\rm T} ≠ 0$&nbsp; and/or &nbsp;$ϕ_{\rm N} ≠ 0$&nbsp; at the same frequencies.&nbsp; However, complex rotation factors must then be added to the weights &nbsp;$A_{\rm N}/4$&nbsp;.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">#</ins>The Dirac lines remain for &nbsp;$ϕ_{\rm T} ≠ 0$&nbsp; and/or &nbsp;$ϕ_{\rm N} ≠ 0$&nbsp; at the same frequencies.&nbsp; However, complex rotation factors must then be added to the weights &nbsp;$A_{\rm N}/4$&nbsp;.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
</table>
Guenter
https://en.lntwww.de/index.php?title=Modulation_Methods/Double-Sideband_Amplitude_Modulation&diff=51543&oldid=prev
Hwang at 19:49, 2 January 2023
2023-01-02T19:49:27Z
<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 19:49, 2 January 2023</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l210" >Line 210:</td>
<td colspan="2" class="diff-lineno">Line 210:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:Mod_T_2_1_S6_version2.png|right|frame|Spectrum of the analytical signal in two different viewpoints]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:Mod_T_2_1_S6_version2.png|right|frame|Spectrum of the analytical signal in two different viewpoints]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>In the further course of this chapter,&nbsp; for the sake of simplifying the graphs,&nbsp; the spectrum &nbsp;$S_+(f)$&nbsp; of the &nbsp;[[Modulation_Methods/General_Model_of_Modulation#<del class="diffchange diffchange-inline">Beschreibung_des_physikalischen_Signals_mit_Hilfe_des_analytischen_Signals</del>|$\text{analytical signal}$]]&nbsp; is usually given instead of the actual, physical spectrum &nbsp;$S(f)$. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>In the further course of this chapter,&nbsp; for the sake of simplifying the graphs,&nbsp; the spectrum &nbsp;$S_+(f)$&nbsp; of the &nbsp;[[Modulation_Methods/General_Model_of_Modulation#<ins class="diffchange diffchange-inline">Describing_the_physical_signal_using_the_analytic_signal</ins>|$\text{analytical signal}$]]&nbsp; is usually given instead of the actual, physical spectrum &nbsp;$S(f)$. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>As an example,&nbsp; let us consider&nbsp; "DSB-AM with carrier"&nbsp; and the following signals:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>As an example,&nbsp; let us consider&nbsp; "DSB-AM with carrier"&nbsp; and the following signals:</div></td></tr>
</table>
Hwang
https://en.lntwww.de/index.php?title=Modulation_Methods/Double-Sideband_Amplitude_Modulation&diff=51542&oldid=prev
Hwang at 19:42, 2 January 2023
2023-01-02T19:42:50Z
<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
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<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 19:42, 2 January 2023</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l137" >Line 137:</td>
<td colspan="2" class="diff-lineno">Line 137:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*In both bracket expressions, the first Dirac delta function indicates the one for positive frequencies. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*In both bracket expressions, the first Dirac delta function indicates the one for positive frequencies. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The weights of all Dirac delta functions are equal and each is &nbsp;$A_{\rm N}/4$.&nbsp; </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The weights of all Dirac delta functions are equal and each is &nbsp;$A_{\rm N}/4$.&nbsp; </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*The sum of these weights &nbsp; - that is, the integral over&nbsp; $S(f)$ <del class="diffchange diffchange-inline">–</del>&nbsp; is equal to the signal value&nbsp; $s(t = 0) = A_{\rm N}$. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*The sum of these weights &nbsp; - that is, the integral over&nbsp; $S(f)$ <ins class="diffchange diffchange-inline">- </ins>&nbsp; is equal to the signal value&nbsp; $s(t = 0) = A_{\rm N}$. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The Dirac lines remain for &nbsp;$ϕ_{\rm T} ≠ 0$&nbsp; and/or &nbsp;$ϕ_{\rm N} ≠ 0$&nbsp; at the same frequencies.&nbsp; However, complex rotation factors must then be added to the weights &nbsp;$A_{\rm N}/4$&nbsp;.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The Dirac lines remain for &nbsp;$ϕ_{\rm T} ≠ 0$&nbsp; and/or &nbsp;$ϕ_{\rm N} ≠ 0$&nbsp; at the same frequencies.&nbsp; However, complex rotation factors must then be added to the weights &nbsp;$A_{\rm N}/4$&nbsp;.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
</table>
Hwang
https://en.lntwww.de/index.php?title=Modulation_Methods/Double-Sideband_Amplitude_Modulation&diff=51541&oldid=prev
Hwang at 17:24, 2 January 2023
2023-01-02T17:24:13Z
<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
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<col class="diff-marker" />
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 17:24, 2 January 2023</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l86" >Line 86:</td>
<td colspan="2" class="diff-lineno">Line 86:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Due to the operation of this switch,&nbsp; the harmonic oscillation&nbsp; $z(t)$&nbsp; can also be replaced by a periodic&nbsp; (rectangular)&nbsp; square wave signal with identical period duration: </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Due to the operation of this switch,&nbsp; the harmonic oscillation&nbsp; $z(t)$&nbsp; can also be replaced by a periodic&nbsp; (rectangular)&nbsp; square wave signal with identical period duration: </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$z_{\rm R}(t) = \left\{ \begin{array}{c} +1 \\ -1 \\ \end{array} \right.\quad \begin{array}{*{10}c} {\rm{for}} \\ {\rm{for}} \\ \end{array}\begin{array}{*{20}c} {z(t) >0,} \\ {z(t) <0.} \\ \end{array}$$</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$z_{\rm R}(t) = \left\{ \begin{array}{c} +1 \\ -1 \\ \end{array} \right.\quad \begin{array}{*{10}c} {\rm{for}} \\ {\rm{for}} \\ \end{array}\begin{array}{*{20}c} {z(t) >0,} \\ {z(t) <0.} \\ \end{array}$$</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*The modulated signal&nbsp; $s(t)$&nbsp; is then obtained as the product of the source signal &nbsp;$q(t)$&nbsp; and this square wave signal &nbsp;$z_{\rm R}(t)$,&nbsp; whereas in ideal DSB-AM one multiplies&nbsp;$q(t)$&nbsp; by a cosine signal.&nbsp; The carrier &nbsp;$z(t)$&nbsp; is not itself included in the signal&nbsp;$s(t)$.&nbsp; Since this is supplied via the center taps of the transformers, the induced voltages cancel out &nbsp; &rArr; &nbsp; &raquo;'''DSB-AM without carrier'''&laquo;. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*The modulated signal&nbsp; $s(t)$&nbsp; is then obtained as the product of the source signal &nbsp;$q(t)$&nbsp; and this square wave <ins class="diffchange diffchange-inline">'''KORREKTUR: rectangular''' </ins>signal &nbsp;$z_{\rm R}(t)$,&nbsp; whereas in ideal DSB-AM one multiplies&nbsp;$q(t)$&nbsp; by a cosine signal.&nbsp; The carrier &nbsp;$z(t)$&nbsp; is not itself included in the signal&nbsp;$s(t)$.&nbsp; Since this is supplied via the center taps of the transformers, the induced voltages cancel out &nbsp; &rArr; &nbsp; &raquo;'''DSB-AM without carrier'''&laquo;. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
</table>
Hwang
https://en.lntwww.de/index.php?title=Modulation_Methods/Double-Sideband_Amplitude_Modulation&diff=51540&oldid=prev
Hwang at 17:17, 2 January 2023
2023-01-02T17:17:12Z
<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
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<col class="diff-content" />
<col class="diff-marker" />
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 17:17, 2 January 2023</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l58" >Line 58:</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This result is still true if the restrictions made in the last section are removed:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This result is still true if the restrictions made in the last section are removed:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#real-valued spectrum &nbsp;$Q(f)$,&nbsp; </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#real-valued spectrum &nbsp;$Q(f)$,&nbsp; </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>#carrier phase &nbsp;$ϕ_{\rm T} = 0$&nbsp; </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>#carrier phase &nbsp;$ϕ_{\rm T} = 0$<ins class="diffchange diffchange-inline">.</ins>&nbsp; </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In general,&nbsp; this results in a complex-valued spectrum &nbsp;$S(f)$.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In general,&nbsp; this results in a complex-valued spectrum &nbsp;$S(f)$.</div></td></tr>
</table>
Hwang
https://en.lntwww.de/index.php?title=Modulation_Methods/Double-Sideband_Amplitude_Modulation&diff=51539&oldid=prev
Hwang at 17:15, 2 January 2023
2023-01-02T17:15:59Z
<p></p>
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 17:15, 2 January 2023</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l44" >Line 44:</td>
<td colspan="2" class="diff-lineno">Line 44:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The factor &nbsp;$1/2$&nbsp; results from the carrier amplitude &nbsp;$A_{\rm T} = 1$.&nbsp; Thus,&nbsp; $s(t = 0) = q(t = 0)$&nbsp; and the integrals over their spectral functions&nbsp; $S(f)$&nbsp; and &nbsp;$Q(f)$&nbsp; must also be equal. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The factor &nbsp;$1/2$&nbsp; results from the carrier amplitude &nbsp;$A_{\rm T} = 1$.&nbsp; Thus,&nbsp; $s(t = 0) = q(t = 0)$&nbsp; and the integrals over their spectral functions&nbsp; $S(f)$&nbsp; and &nbsp;$Q(f)$&nbsp; must also be equal. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The channel bandwidth &nbsp;$B_{\rm K}$&nbsp; must be at least twice the signal bandwidth &nbsp;$B_{\rm NF}$,&nbsp; which gives the name&nbsp; <br>&raquo;'''Double-Sideband Amplitude Modulation'''&laquo;&nbsp; $\text{(DSB–AM)}$. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The channel bandwidth &nbsp;$B_{\rm K}$&nbsp; must be at least twice the signal bandwidth &nbsp;$B_{\rm NF}$,&nbsp; which gives the name&nbsp; <br>&raquo;'''Double-Sideband Amplitude Modulation'''&laquo;&nbsp; $\text{(DSB–AM)}$. </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*It should be noted that&nbsp;$B_{\rm NF}$ and $B_{\rm K}$&nbsp; are absolute and &nbsp;[[Signal_Representation/<del class="diffchange diffchange-inline">Fourier_Transform_Laws</del>#<del class="diffchange diffchange-inline">Reziprozit.C3.A4tsgesetz_von_Zeitdauer_und_Bandbreite</del>|$\text{non-equivalent bandwidths}$]].&nbsp; The latter are defined over rectangles of equal area and are denoted in our tutorial by&nbsp; $Δf_q$&nbsp; and&nbsp; $Δf_{\rm K}$,&nbsp; resp. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*It should be noted that&nbsp;$B_{\rm NF}$ and $B_{\rm K}$&nbsp; are absolute and &nbsp;[[Signal_Representation/<ins class="diffchange diffchange-inline">Fourier_Transform_Theorems</ins>#<ins class="diffchange diffchange-inline">Reciprocity_Theorem_of_time_duration_and_bandwidth</ins>|$\text{non-equivalent bandwidths}$]].&nbsp; The latter are defined over rectangles of equal area and are denoted in our tutorial by&nbsp; $Δf_q$&nbsp; and&nbsp; $Δf_{\rm K}$,&nbsp; resp. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The spectral function &nbsp;$S(f)$&nbsp; does not include any Dirac-lines at the carrier frequency &nbsp;$(\pm f_{\rm T})$.&nbsp; Therefore, this method is also referred to as&nbsp; "DSB-AM '''without carrier'''". </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The spectral function &nbsp;$S(f)$&nbsp; does not include any Dirac-lines at the carrier frequency &nbsp;$(\pm f_{\rm T})$.&nbsp; Therefore, this method is also referred to as&nbsp; "DSB-AM '''without carrier'''". </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The frequency components </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The frequency components </div></td></tr>
</table>
Hwang
https://en.lntwww.de/index.php?title=Modulation_Methods/Double-Sideband_Amplitude_Modulation&diff=51538&oldid=prev
Hwang at 17:09, 2 January 2023
2023-01-02T17:09:42Z
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 17:09, 2 January 2023</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l30" >Line 30:</td>
<td colspan="2" class="diff-lineno">Line 30:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$Z(f) = {1}/{2} \cdot \delta (f + f_{\rm T})+{1}/{2} \cdot \delta (f - f_{\rm T})\hspace{0.05cm}.$$</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$Z(f) = {1}/{2} \cdot \delta (f + f_{\rm T})+{1}/{2} \cdot \delta (f - f_{\rm T})\hspace{0.05cm}.$$</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Those familiar with the &nbsp;[[Signal_Representation/Fourier_Transform_Laws|laws of spectral transformation]]&nbsp; and in particular with the &nbsp;[[Signal_Representation/The_Convolution_Theorem_and_Operation|Convolution Theorem]]&nbsp; can immediately give a solution for the spectrum &nbsp;$S(f)$&nbsp; of the modulator output signal:</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Those familiar with the &nbsp;[[Signal_Representation/Fourier_Transform_Laws|<ins class="diffchange diffchange-inline">$\text{</ins>laws of spectral transformation<ins class="diffchange diffchange-inline">}$</ins>]]&nbsp; and in particular with the &nbsp;[[Signal_Representation/The_Convolution_Theorem_and_Operation|<ins class="diffchange diffchange-inline">$\text{</ins>Convolution Theorem<ins class="diffchange diffchange-inline">}$</ins>]]&nbsp; can immediately give a solution for the spectrum &nbsp;$S(f)$&nbsp; of the modulator output signal:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$S(f)= Z(f) \star Q(f) = 1/2 \cdot \delta (f + f_{\rm T})\star Q(f)+1/2 \cdot \delta (f - f_{\rm T})\star Q(f) = 1/2 \cdot Q (f + f_{\rm T})+ 1/2 \cdot Q(f - f_{\rm T})</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$S(f)= Z(f) \star Q(f) = 1/2 \cdot \delta (f + f_{\rm T})\star Q(f)+1/2 \cdot \delta (f - f_{\rm T})\star Q(f) = 1/2 \cdot Q (f + f_{\rm T})+ 1/2 \cdot Q(f - f_{\rm T})</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> \hspace{0.05cm}.$$</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> \hspace{0.05cm}.$$</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l36" >Line 36:</td>
<td colspan="2" class="diff-lineno">Line 36:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{BlaueBox|TEXT=</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{BlaueBox|TEXT=</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>$\text{Please note:}$&nbsp; This equation takes into account </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>$\text{Please note:}$&nbsp; This equation takes into account </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*that the convolution of a shifted Dirac delta function &nbsp;$δ(x - x_0)$&nbsp; with an arbitrary function&nbsp;$f(x)$&nbsp; yields the &nbsp; '''shifted function''' &nbsp;$f(x - x_0)$.}} </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*that the convolution of a shifted Dirac delta function &nbsp;$δ(x - x_0)$&nbsp; with an arbitrary function&nbsp;$f(x)$&nbsp; yields the &nbsp<ins class="diffchange diffchange-inline">; &raquo</ins>;'''shifted function'''<ins class="diffchange diffchange-inline">&laquo; </ins>&nbsp;$f(x - x_0)$.}} </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l43" >Line 43:</td>
<td colspan="2" class="diff-lineno">Line 43:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Due to the system-theoretic approach with positive and negative frequencies,&nbsp;$S(f)$&nbsp; is composed of two parts around &nbsp;$\pm f_{\rm T}$,&nbsp; each of which have the same shape as &nbsp;$Q(f)$. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Due to the system-theoretic approach with positive and negative frequencies,&nbsp;$S(f)$&nbsp; is composed of two parts around &nbsp;$\pm f_{\rm T}$,&nbsp; each of which have the same shape as &nbsp;$Q(f)$. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The factor &nbsp;$1/2$&nbsp; results from the carrier amplitude &nbsp;$A_{\rm T} = 1$.&nbsp; Thus,&nbsp; $s(t = 0) = q(t = 0)$&nbsp; and the integrals over their spectral functions&nbsp; $S(f)$&nbsp; and &nbsp;$Q(f)$&nbsp; must also be equal. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The factor &nbsp;$1/2$&nbsp; results from the carrier amplitude &nbsp;$A_{\rm T} = 1$.&nbsp; Thus,&nbsp; $s(t = 0) = q(t = 0)$&nbsp; and the integrals over their spectral functions&nbsp; $S(f)$&nbsp; and &nbsp;$Q(f)$&nbsp; must also be equal. </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*The channel bandwidth &nbsp;$B_{\rm K}$&nbsp; must be at least twice the signal bandwidth &nbsp;$B_{\rm NF}$,&nbsp; which gives the name&nbsp; <br>'''Double-Sideband Amplitude Modulation'''&nbsp; $\text{(DSB–AM)}$. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*The channel bandwidth &nbsp;$B_{\rm K}$&nbsp; must be at least twice the signal bandwidth &nbsp;$B_{\rm NF}$,&nbsp; which gives the name&nbsp; <br><ins class="diffchange diffchange-inline">&raquo;</ins>'''Double-Sideband Amplitude Modulation'''<ins class="diffchange diffchange-inline">&laquo;</ins>&nbsp; $\text{(DSB–AM)}$. </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*It should be noted that&nbsp;$B_{\rm NF}$ and $B_{\rm K}$&nbsp; are absolute and &nbsp;[[Signal_Representation/Fourier_Transform_Laws#Reziprozit.C3.A4tsgesetz_von_Zeitdauer_und_Bandbreite|non-equivalent bandwidths]].&nbsp; The latter are defined over rectangles of equal area and are denoted in our tutorial by&nbsp; $Δf_q$&nbsp; and&nbsp; $Δf_{\rm K}$,&nbsp; resp. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*It should be noted that&nbsp;$B_{\rm NF}$ and $B_{\rm K}$&nbsp; are absolute and &nbsp;[[Signal_Representation/Fourier_Transform_Laws#Reziprozit.C3.A4tsgesetz_von_Zeitdauer_und_Bandbreite|<ins class="diffchange diffchange-inline">$\text{</ins>non-equivalent bandwidths<ins class="diffchange diffchange-inline">}$</ins>]].&nbsp; The latter are defined over rectangles of equal area and are denoted in our tutorial by&nbsp; $Δf_q$&nbsp; and&nbsp; $Δf_{\rm K}$,&nbsp; resp. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The spectral function &nbsp;$S(f)$&nbsp; does not include any Dirac-lines at the carrier frequency &nbsp;$(\pm f_{\rm T})$.&nbsp; Therefore, this method is also referred to as&nbsp; "DSB-AM '''without carrier'''". </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The spectral function &nbsp;$S(f)$&nbsp; does not include any Dirac-lines at the carrier frequency &nbsp;$(\pm f_{\rm T})$.&nbsp; Therefore, this method is also referred to as&nbsp; "DSB-AM '''without carrier'''". </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The frequency components </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The frequency components </div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l77" >Line 77:</td>
<td colspan="2" class="diff-lineno">Line 77:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Ring modulator==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Ring modulator==</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>One possibility to realize&nbsp; "double-sideband amplitude modulation with carrier suppression"&nbsp; is offered by a so-called&nbsp; '''ring modulator''',&nbsp; also known as&nbsp; "double push-pull diode modulator".&nbsp; Below you can see the circuit on the left and a simple functional diagram on the right.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>One possibility to realize&nbsp; "double-sideband amplitude modulation with carrier suppression"&nbsp; is offered by a so-called&nbsp<ins class="diffchange diffchange-inline">; &raquo</ins>;'''ring modulator'''<ins class="diffchange diffchange-inline">&laquo;</ins>,&nbsp; also known as&nbsp; "double push-pull diode modulator".&nbsp; Below you can see the circuit on the left and a simple functional diagram on the right.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Without claiming to be complete, the principle can be stated as follows:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Without claiming to be complete, the principle can be stated as follows:</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l86" >Line 86:</td>
<td colspan="2" class="diff-lineno">Line 86:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Due to the operation of this switch,&nbsp; the harmonic oscillation&nbsp; $z(t)$&nbsp; can also be replaced by a periodic&nbsp; (rectangular)&nbsp; square wave signal with identical period duration: </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Due to the operation of this switch,&nbsp; the harmonic oscillation&nbsp; $z(t)$&nbsp; can also be replaced by a periodic&nbsp; (rectangular)&nbsp; square wave signal with identical period duration: </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$z_{\rm R}(t) = \left\{ \begin{array}{c} +1 \\ -1 \\ \end{array} \right.\quad \begin{array}{*{10}c} {\rm{for}} \\ {\rm{for}} \\ \end{array}\begin{array}{*{20}c} {z(t) >0,} \\ {z(t) <0.} \\ \end{array}$$</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$z_{\rm R}(t) = \left\{ \begin{array}{c} +1 \\ -1 \\ \end{array} \right.\quad \begin{array}{*{10}c} {\rm{for}} \\ {\rm{for}} \\ \end{array}\begin{array}{*{20}c} {z(t) >0,} \\ {z(t) <0.} \\ \end{array}$$</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*The modulated signal&nbsp; $s(t)$&nbsp; is then obtained as the product of the source signal &nbsp;$q(t)$&nbsp; and this square wave signal &nbsp;$z_{\rm R}(t)$,&nbsp; whereas in ideal DSB-AM one multiplies&nbsp;$q(t)$&nbsp; by a cosine signal.&nbsp; The carrier &nbsp;$z(t)$&nbsp; is not itself included in the signal&nbsp;$s(t)$.&nbsp; Since this is supplied via the center taps of the transformers, the induced voltages cancel out &nbsp; &rArr; &nbsp; '''DSB-AM without carrier'''. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*The modulated signal&nbsp; $s(t)$&nbsp; is then obtained as the product of the source signal &nbsp;$q(t)$&nbsp; and this square wave signal &nbsp;$z_{\rm R}(t)$,&nbsp; whereas in ideal DSB-AM one multiplies&nbsp;$q(t)$&nbsp; by a cosine signal.&nbsp; The carrier &nbsp;$z(t)$&nbsp; is not itself included in the signal&nbsp;$s(t)$.&nbsp; Since this is supplied via the center taps of the transformers, the induced voltages cancel out &nbsp; &rArr; &nbsp; <ins class="diffchange diffchange-inline">&raquo;</ins>'''DSB-AM without carrier'''<ins class="diffchange diffchange-inline">&laquo;</ins>. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l195" >Line 195:</td>
<td colspan="2" class="diff-lineno">Line 195:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A comparison of these signal waveforms shows:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A comparison of these signal waveforms shows:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*By adding the DC component &nbsp;$A_{\rm T}$&nbsp; the signal &nbsp;$q(t)$&nbsp; can now be seen in the envelope of &nbsp;$s(t)$. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*By adding the DC component &nbsp;$A_{\rm T}$&nbsp; the signal &nbsp;$q(t)$&nbsp; can now be seen in the envelope of &nbsp;$s(t)$. </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*Thus,&nbsp; [[Modulation_Methods/Envelope_Demodulation|envelope demodulation]]&nbsp; can be applied,&nbsp; which is easier and cheaper to implement than coherent &nbsp;[[Modulation_Methods/Synchronous_Demodulation|synchronous demodulation]].</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*Thus,&nbsp; [[Modulation_Methods/Envelope_Demodulation|<ins class="diffchange diffchange-inline">$\text{</ins>envelope demodulation<ins class="diffchange diffchange-inline">}$</ins>]]&nbsp; can be applied,&nbsp; which is easier and cheaper to implement than coherent &nbsp;[[Modulation_Methods/Synchronous_Demodulation|<ins class="diffchange diffchange-inline">$\text{</ins>synchronous demodulation<ins class="diffchange diffchange-inline">}$</ins>]].</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*However,&nbsp; a prerequisite for the application of the envelope demodulator is a modulation depth &nbsp;$m <1$.&nbsp; </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*However,&nbsp; a prerequisite for the application of the envelope demodulator is a modulation depth &nbsp;$m <1$.&nbsp; </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*This parameter is defined as follows:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*This parameter is defined as follows:</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l210" >Line 210:</td>
<td colspan="2" class="diff-lineno">Line 210:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:Mod_T_2_1_S6_version2.png|right|frame|Spectrum of the analytical signal in two different viewpoints]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:Mod_T_2_1_S6_version2.png|right|frame|Spectrum of the analytical signal in two different viewpoints]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>In the further course of this chapter,&nbsp; for the sake of simplifying the graphs,&nbsp; the spectrum &nbsp;$S_+(f)$&nbsp; of the &nbsp;[[Modulation_Methods/General_Model_of_Modulation#Beschreibung_des_physikalischen_Signals_mit_Hilfe_des_analytischen_Signals|analytical signal]]&nbsp; is usually given instead of the actual, physical spectrum &nbsp;$S(f)$. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>In the further course of this chapter,&nbsp; for the sake of simplifying the graphs,&nbsp; the spectrum &nbsp;$S_+(f)$&nbsp; of the &nbsp;[[Modulation_Methods/General_Model_of_Modulation#Beschreibung_des_physikalischen_Signals_mit_Hilfe_des_analytischen_Signals|<ins class="diffchange diffchange-inline">$\text{</ins>analytical signal<ins class="diffchange diffchange-inline">}$</ins>]]&nbsp; is usually given instead of the actual, physical spectrum &nbsp;$S(f)$. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>As an example,&nbsp; let us consider&nbsp; "DSB-AM with carrier"&nbsp; and the following signals:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>As an example,&nbsp; let us consider&nbsp; "DSB-AM with carrier"&nbsp; and the following signals:</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l228" >Line 228:</td>
<td colspan="2" class="diff-lineno">Line 228:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Amplitude modulation with a quadratic characteristic curve==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Amplitude modulation with a quadratic characteristic curve==</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Nonlinearities are usually undesirable and troublesome in Communications Engineering.&nbsp; As explained in the chapter &nbsp;[[Linear_and_Time_Invariant_Systems/Nonlinear_Distortions|Nonlinear Distortions]] &nbsp; of the book&nbsp; "Linear and Time Invariant Systems”,&nbsp; they lead to the facts that:</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Nonlinearities are usually undesirable and troublesome in Communications Engineering.&nbsp; As explained in the chapter &nbsp;[[Linear_and_Time_Invariant_Systems/Nonlinear_Distortions|<ins class="diffchange diffchange-inline">"</ins>Nonlinear Distortions<ins class="diffchange diffchange-inline">"</ins>]] &nbsp; of the book&nbsp; "Linear and Time Invariant Systems”,&nbsp; they lead to the facts that:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*the superposition principle is no longer applicable,</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*the superposition principle is no longer applicable,</div></td></tr>
</table>
Hwang
https://en.lntwww.de/index.php?title=Modulation_Methods/Double-Sideband_Amplitude_Modulation&diff=50198&oldid=prev
Hwang at 10:14, 17 November 2022
2022-11-17T10:14:03Z
<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 10:14, 17 November 2022</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l56" >Line 56:</td>
<td colspan="2" class="diff-lineno">Line 56:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$S(f) = Z(f) \star Q(f)\hspace{0.2cm}\bullet\!\!-\!\!\!-\!\!\!-\!\!\circ\, \hspace{0.2cm} s(t) = q(t) \cdot z(t) = q(t) \cdot \cos(\omega_{\rm T}\cdot t + \phi_{\rm T})\hspace{0.05cm}.$$</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:$$S(f) = Z(f) \star Q(f)\hspace{0.2cm}\bullet\!\!-\!\!\!-\!\!\!-\!\!\circ\, \hspace{0.2cm} s(t) = q(t) \cdot z(t) = q(t) \cdot \cos(\omega_{\rm T}\cdot t + \phi_{\rm T})\hspace{0.05cm}.$$</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:Mod_T_2_1_S2a_version2.png|right|frame|Models of DSB–AM without carrier]] </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:Mod_T_2_1_S2a_version2.png|right|frame|Models of DSB–AM without carrier]] </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>This result is still true if the restrictions made <del class="diffchange diffchange-inline">on </del>the last <del class="diffchange diffchange-inline">page </del>are removed:</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>This result is still true if the restrictions made <ins class="diffchange diffchange-inline">in </ins>the last <ins class="diffchange diffchange-inline">section </ins>are removed:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#real-valued spectrum &nbsp;$Q(f)$,&nbsp; </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#real-valued spectrum &nbsp;$Q(f)$,&nbsp; </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#carrier phase &nbsp;$ϕ_{\rm T} = 0$&nbsp; </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#carrier phase &nbsp;$ϕ_{\rm T} = 0$&nbsp; </div></td></tr>
</table>
Hwang
https://en.lntwww.de/index.php?title=Modulation_Methods/Double-Sideband_Amplitude_Modulation&diff=46455&oldid=prev
Reed at 14:40, 24 March 2022
2022-03-24T14:40:22Z
<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 14:40, 24 March 2022</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l135" >Line 135:</td>
<td colspan="2" class="diff-lineno">Line 135:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This result,&nbsp; which would also have been arrived at via convolution,&nbsp; states:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This result,&nbsp; which would also have been arrived at via convolution,&nbsp; states:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The spectrum consists of four Dirac lines at frequencies &nbsp;$±(f_{\rm T} + f_{\rm N})$&nbsp; and &nbsp;$±(f_{\rm T} - f_{\rm N})$.&nbsp; </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The spectrum consists of four Dirac lines at frequencies &nbsp;$±(f_{\rm T} + f_{\rm N})$&nbsp; and &nbsp;$±(f_{\rm T} - f_{\rm N})$.&nbsp; </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*In both bracket expressions the first Dirac delta function indicates the one for positive frequencies. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*In both bracket expressions<ins class="diffchange diffchange-inline">, </ins>the first Dirac delta function indicates the one for positive frequencies. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The weights of all Dirac delta functions are equal and each is &nbsp;$A_{\rm N}/4$.&nbsp; </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The weights of all Dirac delta functions are equal and each is &nbsp;$A_{\rm N}/4$.&nbsp; </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The sum of these weights &nbsp; - that is, the integral over&nbsp; $S(f)$ –&nbsp; is equal to the signal value&nbsp; $s(t = 0) = A_{\rm N}$. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*The sum of these weights &nbsp; - that is, the integral over&nbsp; $S(f)$ –&nbsp; is equal to the signal value&nbsp; $s(t = 0) = A_{\rm N}$. </div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l146" >Line 146:</td>
<td colspan="2" class="diff-lineno">Line 146:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:EN_Mod_T_2_1_S4.png|right|frame|Typical spectra for DSB-AM]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:EN_Mod_T_2_1_S4.png|right|frame|Typical spectra for DSB-AM]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br></div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*The upper left diagram shows the case just discussed:&nbsp; Both the carrier and the source signal are cosine.&nbsp; Thus,&nbsp; the amplitude modulated signal &nbsp;$s(t)$&nbsp; is composed of two cosine oscillations with &nbsp;$ω_{60} = 2 π · 60\text{ kHz}$&nbsp; and &nbsp;$ω_{40} = 2 π · 40\text{ kHz}$.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*The upper left diagram shows the case just discussed:&nbsp; Both the carrier and the source signal are cosine.&nbsp; Thus,&nbsp; the amplitude<ins class="diffchange diffchange-inline">-</ins>modulated signal &nbsp;$s(t)$&nbsp; is composed of two cosine oscillations with &nbsp;$ω_{60} = 2 π · 60\text{ kHz}$&nbsp; and &nbsp;$ω_{40} = 2 π · 40\text{ kHz}$.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*For the other three constellations,&nbsp; at least one of the signals &nbsp;$q(t)$&nbsp; or &nbsp;$z(t)$&nbsp; is sinusoidal,&nbsp; so that &nbsp;$s(0) = 0$&nbsp; always holds.&nbsp; Thus,&nbsp; for these spectra,&nbsp; the sum of the four <del class="diffchange diffchange-inline">impulse </del>weights each add up to zero.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*For the other three constellations,&nbsp; at least one of the signals &nbsp;$q(t)$&nbsp; or &nbsp;$z(t)$&nbsp; is sinusoidal,&nbsp; so that &nbsp;$s(0) = 0$&nbsp; always holds.&nbsp; Thus,&nbsp; for these spectra,&nbsp; the sum of the four <ins class="diffchange diffchange-inline">pulse </ins>weights each add up to zero.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
</table>
Reed