modelabcd.m

《Home Networking Basis》（《家庭网络基础》）的配套MATLAB源代码。包括了以太网和无线以太网等模型。

f=[1:1025]/1025*20e6;
r1=133;
r2=14;
r3=95.3;
r4=95.3;
r5=68.1;
r6=649;
l=5.6e-6;
c=560e-12;
[a1,b1,c1,d1]=blockabcd(r1,r2,r3,r4,r5,r6,l,c,f);
r1=2320;
r2=1;
r3=95.3;
r4=95.3;
r5=3.83;
r6=11300;
l=0.68e-6;
c=68e-12;
[a2,b2,c2,d2]=blockabcd(r1,r2,r3,r4,r5,r6,l,c,f);
r1=14000;
r2=1;
r3=95.3;
r4=95.3;
r5=1;
r6=10000;
l=0.82e-6;
c=82e-12;
[a3,b3,c3,d3]=blockabcd(r1,r2,r3,r4,r5,r6,l,c,f);
r1=22600;
r2=1;
r3=95.3;
r4=95.3;
r5=0;
r6=11800;
l=0.82e-6;
c=82e-12;
[a4,b4,c4,d4]=blockabcd(r1,r2,r3,r4,r5,r6,l,c,f);
a12=a1.*a2+b1.*c2;
b12=a1.*b2+b1.*d2;
c12=c1.*a2+d1.*c2;
d12=c1.*b2+d1.*d2;
a34=a3.*a4+b3.*c4;
b34=a3.*b4+b3.*d4;
c34=c3.*a4+d3.*c4;
d34=c3.*b4+d3.*d4;
a1234=a12.*a34+b12.*c34;
b1234=a12.*b34+b12.*d34;
c1234=c12.*a34+d12.*c34;
d1234=c12.*b34+d12.*d34;
[imp,h]=abcd2hbk(a1234,b1234,c1234,d1234);
figure(1)
plot(f,20*log10(abs(h(1:1025))));
grid
xlabel('Frequency (Hz)')
ylabel('Magnitude (dB)')