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THE BELL SYSTEM TECHNICAL JOURNAL, JULY 195G 



FERRITE-K- 



Fig. 5 — Electric field distortion. 



ferent in magnitude corresponding to the two directions of propagation. 

 Hence, if resistance material is placed at the interior face of the ferrite 

 (see Fig. 1) we may expect to absorb more energy in one direction of 

 propagation. 



B. Analysis of Electric Field Null:-Full Height Ferrite 



The description we have given in Section IIA is based on a perturba- 

 tion approach and does not take into account the higher order interac- 

 tion effects of the ferrite and the propagating wave. In this section we 

 consider an analysis of the idealized case, namely that of a full height 

 ferrite slab, and impose the condition of an electric field null at the face 

 of the ferrite for the forward direction of propagation. While this too 

 does not represent the true experimental situation, we believe it to be a 

 better approximation than the "point-field" perturbation viewpoint. 



The fields of the various regions shown in Fig. 6 are described as 

 follows : 



E^ 



(1) 



sm a]X 



E,^'^ = Ae-'"'''' -^ 5e'"^"' where x = x 

 ^,"^ = V sin aix" where x" = x - L 



a 



(II -1) 



where 



aj = transverse wave number in the j*'^ region 

 a = transverse dimension from narrow wall to ferrite face 

 L = broad waveguide dimension 

 X = variable dimension along broad face 

 z = height variable 

 A, B, V = constants 

 Setting up the wave equation, there results 



