FIR filter

FIR FILTER USING RECTANGULAR WINDOW

 clc;close all;clear all;

rp=input('enter the passband ripple');

rs=input('enter the stopband ripple');

fp=input('enter the passband ripple');

fs=input('enter the stopband ripple');

f=input('enter the sampling frequency');

wp=2*fp/f;

ws=2*fs/f;

num=-20*log10(sqrt(rs*rp))-13;

dem=14.6*(fs-fp)/f;

n=ceil(num/dem);

if(rem(n,2)~=0)

    n=n1;

    n=n-1;

end

y=RECTWIN(n1);

%bandpass filter

wn=[wp ws];

b=fir1(n,wn,y);

[h,o]=freqz(b,1,256);

m=20*log10*(abs(h));

an=angle(h);

subplot(2,1,1);

plot(o/pi,m);

xlabel('normalised freq-->');

ylabel('gain in db-->');

subplot(2,1,2);

plot(0/pi,an);

xlabel('normalised freq-->');

ylabel('phase in radians-->');