■iR.issMissiox ch.ih.uthristics or WAyr.-vii.iF.Rs .w 



mid-shunt, anil mid-lialf st^ctions, usually tlissimilar, so coniici ti.'d 

 s»riall>' and of surh typi-s that at any junction the torniinations of 

 the two adjacent t\|X's corrcsiiond to an c(iuivak'nt iniajje inii)odani"e. 

 The use of dissiniilar sections gives a resultant selective character- 

 istic ditTerent from that possii)le with a uniform tyix-. At the terminals 

 of the network there need not be complete full or half sections; this 



Fig. 2 — General Composite Wave-Filter Network 



is represented in Fig. 2 by the wave-filter parts e.Mernal to the mid- 

 parl which latter is included between terminals a and b. 



The terminations of wave-filter networks specifically considered 

 in detail here include all terminations which have been found to be 

 practical. In any particular class of wave-filter they are all closely 

 related to the "constant k" wave-filter (2uZ2t = *"=constant) of that 

 class and are of the following four types,' being designated by their 

 characteristic impedances in corresponding ladder type structures. 



' It is assumed that the reader is familiar with the terms and notation used in 

 the paper. B.S.T.J., Jan., 1923. 



If ru and Zu, are the series and shunt impedances of the "constant k" wave-filter, 

 the corresponding series and shunt impedances of the mid-series "const int *" equiva- 

 lent .U-type are expressible as 



rii=miu. 



and of the mid-shunt "constant k" equivalent .l/-type 



1 



mzn 



Am 



and Zn — — z-u,- 



m 



Here the condition Q<m ^ 1 is sufficient for a physical structure in all cases. 



