Finding order of Chebyshev filter of type-2
[n,Wn] = cheb2ord(Wp,Ws,Rp,Rs) [n,Wn] = cheb2ord(Wp,Ws,Rp,Rs,'s')
Normalized passband edge frequency.
Normalized stopband edge frequency.
Allowable passband ripple in dB.
Allowable stopband attenuation in dB.
It computes the order of a type-2 chebyshev filter using the specified parameters Wp, Ws, Rp and Rs. For lowpass and highpass filters, Wp and Ws are single valued. For lowpass filters, Wp is less than Ws and for highpass filters Wp is greater than Ws. For bandpass and bandstop filters, Wp and Ws are arrays having two elements. For bandpass filters Ws(1) is greater than Wp(1), Wp(2) is less than Ws(2). For bandstop filters, Wp(1) is less than Ws(1) and Wp(2) is less than Ws(2). The function also computes the type-2 Chebyshev natural frequency corresponding to the given specifications. By default, the fifth input parameter is 'z'. If it is 's', filter order n, frequency Wn corresponds to the type-2 Chebyshev analog filter.