Parks-mcclellan bandpass filter

1. How does FIrpm work?
2. How to use Firpm in Matlab?
3. How to use fir2 in Matlab?
4. What is extremal frequencies?

How does FIrpm work?

firpm designs a linear-phase FIR filter using the Parks-McClellan algorithm [2]. The Parks-McClellan algorithm uses the Remez exchange algorithm and Chebyshev approximation theory to design filters with an optimal fit between the desired and actual frequency responses.

How to use Firpm in Matlab?

If you specify an odd-valued n , firpm increments it by 1. b = firpm(n,f,a,w) uses the weights in vector w to weight the fit in each frequency band. The length of w is half the length of f and a , so there is exactly one weight per band. b = firpm(n,f,a,w) is a synonym for b = firpm(n,f,@ firpmfrf ,a,w).

How to use fir2 in Matlab?

b = fir2( n , f,m ) returns an n th-order FIR filter with frequency-magnitude characteristics specified in the vectors f and m . The function linearly interpolates the desired frequency response onto a dense grid and then uses the inverse Fourier transform and a Hamming window to obtain the filter coefficients.

What is extremal frequencies?

The extremal frequencies are the maximum and minimum points in the stop and pass bands. The stop band ripple is the lower portion of ripples on the bottom right of the plot and the pass band ripple is the upper portion of the ripples on the top left of the plot.