*3rd order symbolic CRFB delta-sigma
* symbolic parameters, numeric k
in 10 b1
in 20 b2
in 30 b3
in 40 b4
10 20 1/(z-1)
20 30 1*z/(z-1)
30 40 1/(z-1)
40 out k
out 10 -a1
out 20 -a2
out 30 -a3
40 20 -g1
*40 10 -g2
.pre syms z c1 c2 c3 a1 a2 a3 g1 b1 b2 b3 b4
.pre k=1;
.tf in out
.tf out out
*.post syms w;z=exp(j*w);