THE FIELD DISPLACEMENT ISOLATOR 



881 



looking along the direction of the dc magnetic field shown in Fig. 4. 

 Since the major component of circular polarization for (+?/) propagation 

 is also counterclockwise the permeability will be less than unity for this 

 direction of propagation. This occurs provided we are using small static 

 fields, as is readily verified from Fig. 2. The permeability will be greater 

 than unity for ( — y) propagation. Physically, this is equivalent to energy 

 being crowded out of the ferrite for ( + ^) propagation and to energy 

 being crowded in, in the reverse direction. The electric field will thus be 

 distorted as shown in a qualitative way in Fig. 5. The vertical dimen- 

 sion in this figure serves both to identify the guide configuration and to 

 provide an ordinate for the electric field intensity. 



The fields as shown in Fig. 5 merely represent a (iualitative picture of 

 the distributions in the guide and are not intended to be exact. There is 

 no question, however, that the electric fields at the ferrite face are dif- 



Fig. 3 — Magnetic field configuration — Dominant TEjo mode. 



Hoc 



FERRITE 

 ELEMENT 



^,w/^////j / y/////Ay/yyy^/ /^^^////^^^^^^^^^^^y/-'/w////y'^. 



RESISTANCE STRIP 



;^ /////,v.vy/yy/-^^^/'y/yy^/V////'-^y^yy^ vAvyyyy^^/yy/////-^////^^ 



-4<-d-A 



, 1_ 



Fig. 4 — Experimental configuration. 



