820 



BELL SYSTEM TECHNICAL JOURNAL 



this susceptance to a suitable approximation. Fortunately the 

 characteristics required of this network are of a type which can readily 

 be obtained with physically realizable elements. The curves of Figs. 

 9 and 10 represent the susceptance characteristics required for the 



UJ 



u 

 z 

 < 



u 

 < 



cr 

 o 



'^ 



N 

 X 



UJ 



u 



0. 



llJ 

 o 

 it) 



D 



1.4 



1.3 



1.2 



I.I 



-In i.o 



0.9 



0.8 



0.7 



0.6 



0.5 



0.4 



0.3 



0.2 



0.1 



0.1 



0.2 



0.3 



0.4 



0.5 



0.6 



0.7 



0.8 



0.9 



1.0 



Fig. 10 — Reactance and susceptance characteristics secured from expansion in terms 



of Legendrian harmonics. 



Legendrian and binomial expansion networks. Empirically deter- 

 mined networks give very similar results. The general configuration 

 of appropriate susceptance correcting networks can be determined 

 from an inspection of these curves. For example, if we assume that 

 a low pass filter is in question, which means that the variable "x" 



