Frequency response of <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle H(j\omega )={\frac {1}{3}}\left(1+e^{-j\omega }+e^{-j2\omega }\right)}"><semantics><mrow class="MJX-TeXAtom-ORD"><mstyle displaystyle="true" scriptlevel="0"><mi>H</mi><mo stretchy="false">(</mo><mi>j</mi><mi>ω<!-- ω --></mi><mo stretchy="false">)</mo><mo>=</mo><mrow class="MJX-TeXAtom-ORD"><mfrac><mn>1</mn><mn>3</mn></mfrac></mrow><mrow><mo>(</mo><mrow><mn>1</mn><mo>+</mo><msup><mi>e</mi><mrow class="MJX-TeXAtom-ORD"><mo>−<!-- − --></mo><mi>j</mi><mi>ω<!-- ω --></mi></mrow></msup><mo>+</mo><msup><mi>e</mi><mrow class="MJX-TeXAtom-ORD"><mo>−<!-- − --></mo><mi>j</mi><mn>2</mn><mi>ω<!-- ω --></mi></mrow></msup></mrow><mo>)</mo></mrow></mstyle></mrow><annotation encoding="application/x-tex">{\displaystyle H(j\omega )={\frac {1}{3}}\left(1+e^{-j\omega }+e^{-j2\omega }\right)}</annotation></semantics></math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/5b67046e2b47a226f2d425294adb8fcc0e68496b" class="mwe-math-fallback-image-inline" aria-hidden="true" style="vertical-align: -1.838ex; width:30.144ex; height:5.176ex;" alt="{\displaystyle H(j\omega )={\frac {1}{3}}\left(1+e^{-j\omega }+e^{-j2\omega }\right)}"></span>. The top plot is the magnitude plot and the bottom plot is the phase plot.  At the two frequencies where the magnitude goes to zero, there is a sign reversal which causes the phase discontinuities by π radians.  Thus they are true discontinuities, not artifacts of <a href="https://en.wikipedia.org/wiki/Instantaneous_phase" class="extiw" title="w:Instantaneous phase">phase wrapping</a>.
<a href="//commons.wikimedia.org/wiki/User:Krishnavedala" title="User:Krishnavedala">Krishnavedala</a>
2011-06-12
<span class="int-own-work" lang="en">Own work</span>