GUIDED AVAVE PROPAGATION THROUGH GYROMAGNETIC MEDIA. Ill 1151 



sample, for instance). The matching could be accomphshed in such a 

 way that the transition region, whose characteristics would be very diffi- 

 cult to compute, should contribute little to the overall non-reciprocal 

 beha\'ior. Therefore, in many cases, the theory for the indefinitely ex- 

 tended sample is adequate. For some special purposes, however, it is 

 desirable to mismatch the sample deliberately. For instance, Howen' 

 has suggested that the change in Faraday rotation, due to internal re- 

 flections in an unmatched specimen, can offset to some extent the fre- 

 quency dependence of the rotation which is implied by the Polder rela- 

 tions, broadening thereby the useful band\\idth of the device. 



Consider an infinite slab of ferrite, magnetized in a direction normal 

 to its two parallel plane bounding surfaces. A circularly polarized wave, 

 normally incident on the slab, A\ill be partially transmitted, and, since 

 for such a wave, the medium behaves as though it had an ordinary scalar 

 permeability, the phase and amplitude of the transmitted portion are 

 readily calculated. It is clear that, as the result of multiple internal re- 

 flections, the phase of the emerging wave AAnll differ from the value ap- 

 propriate to a single trip through the slab (such as would be obtained 

 were the slab perfectly matched). Both amplitude and phase of the 

 transmitted wave aWII depend on the electrical thickness of the slab and 

 its dielectric constant, and on the effective permeability. The latter 



dc 



0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 



C= n/Po 



Fig. 2 7 — ^ versus — . 



a 



fe) 



