1162 THE BELL SYSTEM TECHNICAL JOURNAL, NOVEMBER 1952 



the pth mode in a parallel-plane Clogston 2, with the same number of 

 field maxima and field reversals for a given value of p, though of course 

 the spacings and amplitudes of the field maxima are not all equal in 

 the coaxial cable. 



As numerical examples we have plotted in Figs. 18 and 19 the fields 

 of the second and third stack modes (i.e., the first and second higher 

 modes) in the same two Clogston cables which were used to show the 

 principal mode in Fig. 14. The horizontal scales on these figures are 

 arbitrary and have no relation to one another. Figs. 18(a) and 19(a) 

 represent a partially filled cable with the same dimensions, namely 

 a = 0.0846, pi = 0.4156, and pa = 0.8316, as in Fig. 14(a), while 

 Figs. 18(b) and 19(b) represent a completely filled cable, as in Fig. 14(b). 

 The following table shows, as a function of the filling ratio (si + S2)/6, 

 the quantity (xp6/3.83)^ for p = 1, 2, 3; this quantity is just the ratio 

 of the attenuation constant of the given mode to the attenuation con- 

 stant of the principal mode in a completely filled Clogston 2. 



We note that although the proportions of the partially filled cable were 

 found in Section IX to be optimum, in the sense of minimizing the at- 

 tenuation constant, for the principal mode in a cable with filling ratio 

 0.5, there is no reason to believe that the same proportions will be opti- 

 mum for the second and third modes with the same filling ratio. 



H.=# 



H OR E 



H OR E 



Fig. 18 — Fields of second stack mode in partially and completely filled coaxial 

 Clogston lines with fio = m, eo = «. 



