Naveed Ahmed
Member level 4
Hi,
I have written a test program in matlab for lowpass fir, when i m plotting its magnitude response after fft, it seems to be a high pass filter. Why its doing so??
My code is as follow:
N=50; %Filter order
Length=N+1; %length
n0=N/2; %delay parameter
n=0:1:N;
fc_l=1/8; %Cut off frequency for the low pass filter
Wc_l=2*pi*fc_l;
%===================LOWPASS FIR FILTER=====
h_lp=sin(Wc_l*(n-n0)) ./(pi*(n-n0)); %Impulse response of Low Pass FIR filter For n-n0!=0
h_lp(n0+1)=(Wc_l/pi) %Imp response of Low Pass FIR filter For n=n0 or n-n=0
F=fft(h_lp,51);
X=real(F);
Y=imag(F);
[th,Mag]=cart2pol(X,Y);
plot(0:50,Mag)
Thnks,
ur comments plz
naveed
I have written a test program in matlab for lowpass fir, when i m plotting its magnitude response after fft, it seems to be a high pass filter. Why its doing so??
My code is as follow:
N=50; %Filter order
Length=N+1; %length
n0=N/2; %delay parameter
n=0:1:N;
fc_l=1/8; %Cut off frequency for the low pass filter
Wc_l=2*pi*fc_l;
%===================LOWPASS FIR FILTER=====
h_lp=sin(Wc_l*(n-n0)) ./(pi*(n-n0)); %Impulse response of Low Pass FIR filter For n-n0!=0
h_lp(n0+1)=(Wc_l/pi) %Imp response of Low Pass FIR filter For n=n0 or n-n=0
F=fft(h_lp,51);
X=real(F);
Y=imag(F);
[th,Mag]=cart2pol(X,Y);
plot(0:50,Mag)
Thnks,
ur comments plz
naveed