790 



BELL SYSTEM TECHNICAL JOURNAL 



Attenuation of Impedance Correcting Sections Reduces Net Cost of 



Impedance Correctioji 



The economic aspects of filter design demand some sort of an evalua- 

 tion of the cost of improving filter impedances. While the terminat- 



24 



20 





Z 16 



if) 



O 

 -I 12 



Z 



o 



a. 



Hi 



z 



0.9 1.0 



1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 



X 



Fig. 20 — Insertion loss of a 2-branch termination. 



0.9 1.0 



1.2 



1.3 



1.4 



1.5 

 X 



1.6 



1.7 



1.8 



2.0 2.1 



Fig. 21 — Insertion loss of a 2-branch termination. 



ing sections shown in Fig. 12 are rather complicated, their cost is dis- 

 counted considerably by the fact that they contribute appreciably to 

 the attenuation of the structure as a whole to undesired frequencies. 



