CURVED WA VE GUIDES 



27 



In the second region, between points 2 and 3, the polarity of Ro , and 

 consequently of k. and the ratio of TM to TE ampUtudes, are reversed. 



a -CIRCULAR S BEND5 



b- SINUSOIDAL BENDS 

 Fig. 5 



Except for this change of polarity the amplitude ratios at points 1 and 2 

 are equal. Introducing the symbols 



— TsTrt 



S = e 



gm = h(ga + gb) 

 gd = Ugh- go) 



one can tabulate 

 point 



1 

 2 



a + b 



^TM 



aA 



A 



'' + bg'i ) g"^ ( ^- - j Sd 



Calling = y, one finds 

 a 



I I 2 i2 , 2 



1 + ygd ^ -A + yga 

 1 + y A^ - y 



^average 



7-1 

 7-2 



