find_freq - parameter compatibility for elliptic filter design

Calling Sequence

[m]=find_freq(epsilon,A,n)

Parameters

• epsilon : passband ripple
• A : stopband attenuation
• n : filter order
• m : frequency needed for construction of elliptic filter

Description

Search for m such that n=K(1-m1)K(m)/(K(m1)K(1-m)) with

m1=(epsilon*epsilon)/(A*A-1);

If m = omegar^2/omegac^2, the parameters epsilon,A,omegac,omegar and n are then compatible for defining a prototype elliptic filter. Here, K=%k(m) is the complete elliptic integral with parameter m.

See Also

%k  

Author

F. D.