cheb2mag

Arguments

n

integer ; filter order

omegar

real scalar : cut-off frequency

A

attenuation in stop band

sample

vector of frequencies where cheb2mag is evaluated

h2

vector of Chebyshev II filter values at sample points

Description

Square magnitude response of a type 2 Chebyshev filter.

omegar = stopband edge, sample = vector of frequencies where the square magnitude h2 is desired.

Examples

//Chebyshev; ripple in the stopband
n=10;
omegar=6;
A=1/0.2;
Samples=0.0001:0.05:10;
h2=cheb2mag(n,omegar,A,Samples);
plot(Samples,log(h2)/log(10))
xtitle("", "frequencies", "magnitude in dB");

//Plotting of frequency edges
minval=(-max(-log(h2)))/log(10);
plot2d([omegar;omegar],[minval;0],[2],"000");

//Computation of the attenuation in dB at the stopband edge
attenuation=-log(A*A)/log(10);
plot2d(Samples',attenuation*ones(Samples)',[5],"000")

See Also

• cheb1mag — response of Chebyshev type 1 filter