//Ex:19 clc; clear; close; c_nu=316.22;//25;//c/n ratio for earth station c_nd=100;//20;//c/n ratio from a transponder c_n=1/((c_nu)^(-1)+(c_nd^(-1)));//overall c/n ratio printf("The overall c/n ratio=%f db ",c_n); c_ndb=10*log(c_n)/log(10);//overall c/n ratio in db printf("\n The overall c/n ratio=%f db", c_ndb);