FERRTTES IN MICROWAVE APPLK ATIONS 1369 



match impedance-wise. To illustrate the comparison between compar- 

 able devices using each principle we have prepared a figure showing the 

 relative structural complexity and performance standards of each. This 

 comparison is shown in Fig. 22. In general the transverse field devices 

 which depend on differential phase shift have about the same insertion 

 loss as those employing the Faraday effect, while the transverse field 

 devices which depend upon differential absorption are somewhat more 

 lossy but simpler to construct than the corresponding Faraday Ro- 

 tacion devices. 



SUMMARY 



This paper has reviewed the plane wave theory, extended it to discuss 

 waveguide effects, analyzed the various loss mechanisms present in fer- 

 rites at microwaves, and discussed numerous measurement techniques 

 and results. It is known that there are original papers in preparation in 

 Bell Telephone Laboratories, and possibly elsewhere, which make this 

 review incomplete at the time of writing. However, it is hoped that the 

 information summarized herein will be of assistance to those who are 

 seeking orientation in this new and rapidly expanding field. 



In conclusion the author wishes to thank A. G. Fox, M. T. Weiss, 

 J. P. Schafer, H. Suhl, A. D. Perry and L. R. Walker for permission to 

 discuss herein some of their work and ideas which have not previously 

 been published. The cooperation of F. J. Schnettler and L. G. Van 

 Uitert in providing us \vith a mde variety of excellent ferrites and in 

 suggesting useful variations in ferrite properties has been of tremendous 

 help in the advancement of the art. The advice given by C. L. Hogan, 

 J. K. Gait and H. Suhl in discussions has proved invaluable and finally 

 the author wishes to thank J. L. Davis for the able assistance he 

 rendered . 



