396 



THE BELL SYSTEM TECHXICAL JOURNAL, MARCH 1957 



0.454"R 



n =28 EQUIVALENT UNIFORM HOLES 



T=0.022"' °-^^° 



Fig. 2 — 11-kmc coupler sketch. 



_) 



UJ 



m 

 o 



UJ 



o 



to 

 in 



o 



_J 



rr 



UJ 



u. 



z 

 < 



2.6 

 2.4 



2.2 



2.0 

 1.8 

 1.6 

 1.4 



1.2 

 1.0 

 0.8 

 0.6 

 0.4 

 0.2 



9.0 9.4 9.8 10.2 10.6 11.0 11.4 H.8 



FREQUENCY IN KILOMEGACYLES PER SECOND 



12.2 



Fig. 3 — 11-kmc coupler transfer loss. 



