304 

 and 



BKLL SYSTEM TI.CIIMCAL JOURNAL 



W;u = 



R 



VI + U,+ iV, 



In the above < m ^ \. At the limit m = \, the two structures 

 reduce to the "constant k" wave-filter; also IFi/,(w = 1) = Wu- and 

 W2k(m - 1) = IF.,. 



A mid-half section of each of these wave-filters is shown in Fig. 6. 

 It is to be remembered that the transfer constant of a mid-half section 

 is one-half that of the full section given in the formulas. 



MlcC-JwU/ Aeam- M-Jyype 



z 



-o-VvAv-o- 



m 



Jh 



27n ^/h 



•A 7 

 •772/ *^Zh 



K^cm) 



'2h 



MlcC-Jmlf Ahunb M-Jyy^e 



TTh-y 

 2 ^iK 



zm 



i-7n^ ^zhj 



K, 



^zh 



Zo 



7rh*^zh 



w,m 



Fig. 6 — -Alid-half sections of M-type wave-filters. 



To illustrate the propagation and impedance characteristics of 

 ilf- types, as in Fig. 7, the parameter was taken to have the value 

 m = .6. The attenuation constant has one maximum just beyond 

 each critical frequency, where Uh = — 1/(1 — nr) = — 1.5625, and 

 in this particular case the image impedances shown have the fairly 

 constant resistance values over a large part of each transmitting band 

 to which reference has been made. With other values of m there may 



