COUPLED AVAVK TIIIOOKY AND "WAVKCUIDE APPLirATIONS (iOf) 



35 



30 



I 2 3 4 5 6 8 10 20 30 40 60 60 100 



n = NUMBER OF COUPLING UNITS 



Fig. 35 — Loss per coupling unit versus number of coupling units, with the 

 desired transfer loss as a parameter. 



wavegiikles was shown to be possible in a coupling interval two wave- 

 lengths long, and very broad band directivity characteristics of a shape 

 prescribed to meet given requirements were shown to be achievable. 



The following paragraphs report on experiments which \\^\q. been 

 carried out with the objective of developing other useful devices and 

 with the ancillary aim of verifying other predictions of the theory. 



Experimental work was done to verify the cyclical nature of energy 

 transfer between coupled lines, to determine the magnitude of losses 

 which accompany such transfer in the waveguide case, and to determine 

 desirable coupling distribution shapes in the tight coupling case. These 

 experiments were carried out by R. W. Dawson in the 3.1 to 3.5 cm band 

 using the 0.4'' x 0.9" I.D. jig shown in Fig. 30, consisting of two wave- 



Fig. 3f) — A 0.4" X 0.0" I.l). \va\'('guiilc jig used lor '.\ cm couijlcd line cxpcM'i- 

 ments. The long waveguides on one side of the coupling insert were required to 

 accommodate low-reflection terminations for directivity measurements. 



