EllipticFilterModel

EllipticFilterModel[n]
designs a lowpass elliptic filter of order n.

EllipticFilterModel[{n,ωc}]
uses the cutoff frequency ωc.

EllipticFilterModel[{"type",spec}]
designs an elliptic filter of the specified type "type", using the spec.

EllipticFilterModel[{"type",spec},var]
expresses the model in terms of the variable var.

DetailsDetails

  • EllipticFilterModel returns the designed filter as a TransferFunctionModel.
  • EllipticFilterModel[{n,ω}] returns a lowpass filter with attenuation of (approximately 3 dB) at frequency ω.
  • EllipticFilterModel[n] uses the cutoff frequency of 1.
  • Filter specification {"type",spec} can be any of the following:
  • {"Lowpass",{ωp,ωs},{ap,as}}lowpass filter using passband and stopband frequencies and attenuations
    {"Highpass",{ωs,ωp},{as,ap}}highpass filter
    {"Bandpass",{ωs1,ωp1,ωp2,ωs2},{as,ap}}bandpass filter
    {"Bandstop",{ωp1,ωs1,ωs2,ωp2},{ap,as}}bandstop filter
  • Frequency values should be given in an ascending order.
  • Values ap and as are absolute values of passband and stopband attenuations, respectively.
  • Given a gain fraction , the attenuation is .

ExamplesExamplesopen allclose all

Basic Examples  (2)Basic Examples  (2)

A third-order elliptic filter model with cutoff frequency at :

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Bode plot of the filter:

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A lowpass elliptic filter using the full specification:

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Magnitude response of the filter showing the ideal filter characteristics:

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Introduced in 2012
(9.0)