810 



BELL SYSTEM TECHNICAL JOURNAL 



The analyses are stated in terms of conductance and susceptance, since 

 in this form they are most conveniently applied to the impedance 

 correction of systems of parallel filters, which constitute a large propor- 

 tion of practical cases. The formuke and curves can, however, be 

 used directly in analyses stated in terms of impedance if we merely 

 replace conductance and susceptance by resistance and reactance and 

 write Zo in the numerator rather than in the denominator whenever it 



GENERAL CONFIGURATIONS OF TERMINATION 



SUSCEPTANCE 



ANNULLING 



NETWORK 



(n = i) 



(n=2) 



APPROPRIATE 



CONFIGURATIONS 



OF SUSCEPTANCE 



ANNULLING NETWORKS 



K|Z|k 



I 



t^2Z2k 



(n = 3) 



^S 



KiZik 



K2Z2k 



— c:^ 



K3Z|k 



K4Z2K 



Fig. 5 — Configurations of 1, 2 and 3 branch terminations. 



appears. After the relations between ai . . . o„and^i . . . ^„ have 

 been determined we shall proceed to a discussion of methods of choos- 

 ing values oi Ai . . . An giving a suitable resistance or conductance 

 characteristic. The final steps are the computation of the element val- 

 ues of the network from these values of the polynomial coefficients, 

 the calculation of the resulting reactance or susceptance characteristic 

 and the design of a final branch giving the complete structure the 

 desired reactance or susceptance characteristic. 



