FERRITES IN MICROWARE APPLICATIONS 



1359 



20 



16 



O 12 



? 10 



z 

 o 



< 



I- 

 o 



^ 6 



7000 



8000 9000 10,000 11,000 



FREQUENCY IN MEGACYCLES PER SECOND 



12,000 



Fig. 14 — Variation of rotation with frequency showing broadbanding obtained 

 through compensation technique. 



components of the wave. The corresponding relation for the partially 

 filled waveguide will be a transcendental expression involving /x^ and c 

 in a similar way so that arguments regarding the waveguide problem 

 may be based upon equation 15 if we consider /xj. and c to be effective 

 values averaged over the guided mode. Thus by increasing the dielectric 

 constant of the region surrounding the ferrite we increase the rotation by- 

 increasing the average value of c. Since we also change the radial dis- 

 tribution in such a way as to reduce the fraction of the power contained 

 in the ferrite the amplification in rotation will be less than would be 

 obtained if the waveguide diameter were reduced at the same time. In 

 Fig. 16 we show the effect of increasing the dielectric constant of the 

 region surrounding the ferrite and the effect of a subsequent reduction 

 in guide size. Here again we see that if very high dielectric constants 

 were available in low loss materials a really significant improvement in 

 performance could be obtained. Nevertheless, even the effect of the poly- 

 styrene is useful and here we suffer a loss of less than 0.1 db at X-Band. 

 In the discussion of the loss mechanisms the second hump on absorp- 

 tion Curve F in Fig. 5 was described as a "cavity resonance". While the 

 exact mode of resonance cannot be determined except from a complete 

 solution of the partially filled waveguide problem, we are able to show 

 that the subsidiary hump is strongly dependent upon the diameter of 



