THE FIELD DISPLACEMENT ISOLATOR 



897 



loss in the resistive strip, for an idealized ferrite, in the low conductive 

 limit of such a strip. Let 



12 



Er 



V = 



where 77 is the appropriate quantity, Er is the field at the resistance, and 

 P is the total power flow across the guide cross-section. This figure of 

 merit is related to the rate of change of the attenuation constant (A) 

 with respect to strip conductance in the following manner: 



p = 0.0434377/1 (db)(ohms)/cm 



where h is the fractional height of the loss strip, and g is the reciprocal 

 of the surface resistivity in ohms/square. 



The total power flow may be divided into integrations of the Poynting 

 vector over the three regions of the guide cross-section. The following 

 results are obtained normalized to Er = sin aia: 



Region 1: ^ a; ^ a 



p (1) _ 

 Region 2: a ^ x ^ a -\- 8 



(2) /3 / /Xr3 



^ 



2co/xo 



/ sin 2aia\ 



V 2^7 





/ , 2 , , 2n , sin 2a28 



fXridi^ — di) — -^ a2{2did^ 



+ 



1 — cos 2a25 



y.r{2dd2) + ^ id,' - d,') 



Region Z: a -\- b ■^ x S L 



p (3) _ 

 ^y — 



/3 



2cJ)Uo 



h - 



sin 2 a]b\ {d\ cos aih -\- di sin a-^ 



where 

 and 



2q;i 



d\ = sin aia 



sin aj) 



do = 



yird-l 



[{nr — kr)oci cos aitt -f- /cr/3 siu aia] 



