# Wolfram Language & System 10.0 (2014)|Legacy Documentation

This is documentation for an earlier version of the Wolfram Language.
BUILT-IN WOLFRAM LANGUAGE SYMBOL

# EllipticFilterModel

designs a lowpass elliptic filter of order n.

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

EllipticFilterModel[{"type",spec}]
designs an elliptic filter of the specified 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.
• uses machine precision to return a filter with attenuation of at frequency 1.
• In EllipticFilterModel[{"type",spec},var], filter specification can be any of the following:
•  {"Lowpass",{ωp,ωs},{ap,as}} lowpass filter specification {"Highpass",{ωs,ωp},{as,ap}} highpass filter specification {"Bandpass",{ωs1,ωp1,ωp2,ωs2},{as,ap}} bandpass filter specification {"Bandstop",{ωp1,ωs1,ωs2,ωp2},{ap,as}} bandstop filter specification
• Frequency values should be given in an ascending order.
• Values and are absolute values of passband and stopband attenuations, respectively.
• Given a gain fraction , the attenuation .

## ExamplesExamplesopen allclose all

### Basic Examples  (2)Basic Examples  (2)

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

 Out[1]=

Bode plot of the filter:

 Out[2]=

A lowpass elliptic filter using the full specification:

 Out[1]=

Magnitude response of the filter showing the ideal filter characteristics:

 Out[2]=