The pointmatching solution for magnetically tunable cylindrical cavities and ferrite planar resonators
Abstract
This paper presents an exact fieldtheory treatment for a cylindrical cavity containing a fullheight triangular ferrite post as well as for ferrite planar resonators of arbitrary shape. Knowledge of the resonant frequencies of the cavity is essential for the construction of circulators with a triangular ferrite post; those of the planar circuits are needed for the design of microwave integrated circuits. The treatment is general and depends neither on the location of the ferrite post inside the cavity nor on the geometry of the planar resonator. The solution of the wave equations in the ferrite material and in a possible surrounding air region is written as an infinite summation of cylindrical modes. In the case of the cavity, the individual modes are exactly matched along the internal cylindrical metallic boundary of the cavity. The fields at the ferriteair interface in both cases are matched by using the pointmatching technique, which leads to a finite system of homogeneous simultaneous equations for which the determinantal equation must be zero. An example of a cavity with a triangular ferrite post is studied and calculated, and measured results are compared.
 Publication:

IEEE Transactions on Microwave Theory Techniques
 Pub Date:
 June 1979
 DOI:
 10.1109/TMTT.1979.1129677
 Bibcode:
 1979ITMTT..27..592K
 Keywords:

 Boundary Value Problems;
 Cavity Resonators;
 Ferrites;
 Integrated Circuits;
 Magnetic Control;
 Microwave Resonance;
 Circular Cylinders;
 Frequency Control;
 Performance Prediction;
 Prisms;
 Resonant Frequencies;
 Tuning;
 Electronics and Electrical Engineering