Name
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.