filtResp2ndOrderQ

Computes the complex frequency response function of a 2nd-order damped highpass, lowpass, or allpass filter function.

Syntax

h = filtResp2ndOrderQ(f,fc,Q,filtType)

h = filtResp2ndOrderQ(f,fc,Q)

filtRespHPQ(__)

filtRespHPQ()

Description

h = filtResp2ndOrderQ(f,fc,Q,filtType) returns the frequency response column vector computed at the frequencies supplied in f (in Hz). The filter resonance has a frequency of fc (in Hz), and its quality factor (bandwidth) parameter is Q. If Q is a vector of values, the frequency response is returned as a matrix of column vectors.

A highpass filter is specified by setting filtType to be one of the following:

{'H', 'HP', 'HIGHPASS', 'HIGH-PASS'}.

A lowpass filter is specified by setting filtType to be one of the following:

{'L', 'LP', 'LOWPASS', 'LOW-PASS'}.

An allpass filter is specified by setting filtType to be one of the following:

{'A', 'AP', 'ALLPASS', 'ALL-PASS'}.

If filtType is omitted or is empty ([]), then a highpass filter is the default choice.

filtResp2ndOrderQ(__) with no output argument plots the magnitude and phase response of the filter (its frequency response).

filtResp2ndOrderQ() with no input arguments plots the magnitude and phase response of an example second-order filter.