450 BELL SYSTEM TECHNICAL JOURNAL 



where Vb is voltage reflected from coupling BE and V ^ is voltage reflected 

 from termination Z. 



Equations (8) can be solved for Vh and V ^ for 



V 4- V ■ V — V 



F' max 1^ ' mm i t' ' max ' mm /rvN 



5 = and V^ = (.9) 



The incident voltage is measured as before. Therefore, using equation (6) 



W = 20 log 1^1 and W" = 20 log L^' (10) 



where W is due to coupling BE, W" is due to termination Z and Va is 

 incident voltage. 



Fig. 3 — Vector diagram of voltages reflected from coupling BE and termination Z. 



A more practical solution involving only addition, subtraction and the 

 use of the characteristics in Fig. 4 is now presented. The settings of 

 the detector attenuator for incident voltage, minimum output and maxi- 

 mum output might be yli , Az and Ai^ . 



where 20 log 'y^' = T = W" - W (14) 



