174 THE BELL SYSTEM TECHNICAL JOURNAL, JANUARY 1956 



which can be written with (25) and (26) as 

 (jSott cot ipiY cot \f/2 



K(i2 Ri 



[ 



02 ilO 



(7a)- cot \{/i 

 = /oi 



Ri 



loM 



(/3oa cot \l/2)- 



■I 02 — 7 rr, rn 



(34) 



Koiyf) 



This equation together with (29) enables one to evaluate f/a versus j8oa 

 cot \l/i for various ratios of b/a and cot i^2/cot xpi . The results of these 

 calculations are shown in Fig. 3.1. 



5.0 



4.5 



4.0 



3.5 



3.0 



7a 



2.5 



2,0 



0.5 



Fig. 4.1. .3 — The radial propagation constants associated with the transverse 

 and longitudinal modes on coupled coaxial sheath helices given as a finiclion of 

 0oa cot \{/i when b/a = 1.75. 



i 



