Phase Response

Definition. The phase response of an LTI filter is defined as the phase (or angle) of the frequency response :

The phase response is often referred to as the ``phase'' of the filter. For real filters (filters with real coefficients), the filter phase can be defined unambiguously as the phase of its frequency response.

The real-valued phase response gives the phase shift in radians that each input component sinusoid will undergo.

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written by Julius Orion Smith III
Julius Smith's background is in electrical engineering (BS Rice 1975, PhD Stanford 1983). He is presently Professor of Music and Associate Professor (by courtesy) of Electrical Engineering at Stanford's Center for Computer Research in Music and Acoustics (CCRMA), teaching courses and pursuing research related to signal processing applied to music and audio systems. See http://ccrma.stanford.edu/~jos/ for details.