TWO-TERMINAL BALANCING NETWORKS 

 Return Loss 



291 



When designing such networks for balancing purposes, it has been found 

 convenient to plot the function on a sheet such as Fig. 6 which divides the 

 right half of the complex plane into circular regions such that all points on 

 or within the boundary of a given region have a return loss against the 

 network 1 + ^0 equal to or greater than that corresponding to the boundary. 

 These circles are determined by the return loss voltage ratio k and the ratio 



RESISTANCE 



Fig. 6 — Curves of constant return loss for the network 1 ZO = 1 -{-jO. 



of the hne and network impedances. They may be computed from the 

 equation 



(1 + L/N)/(l - L/N) = k (6) 



By plotting the line and simulating network loci on such a sheet it is 

 generally possible to observe visually whether or not a given network meets 

 the specified return loss requirement. If visual accuracy is not adequate, 



