//Caption:Calculate (i)-directivity ,(ii)-coupling, (iii)-isolation //Exa:6.11 clc; clear; close; S_13=0.1; S_14=0.05; C=-20*log(S_13)/log(10); D=20*log(S_13/S_14)/log(10); I=C+D; disp(C,'Coupling (in dB) ='); disp(D,'Directivity (in dB)) ='); disp(I,'Isolation (in dB) =');