The effect of small ellipsoidal material on the resonant frequency of a cavity
Abstract
This report calculates the electromagnetic fields in a resonant cavity when a small ellipsoidal material is present. The medium inside the cavity has no losses and, excited at resonance, the electric and magnetic fields inside the cavity are E(x,y,z,t) = E(sub 0)(x,y,z) e(exp j omega t) and H(x,y,z,t) = H(sub 0)(x,y,z) e(exp j omega t). Insertion of a small piece of material with permittivity and permeability not equal to the values for the medium inside the cavity will change the field values and the resonant frequency. The derived formulas are applied to the cases of a dielectric sphere, a metal sphere, a dielectric needle, a metal needle, a dielectric disk, and a metal needle parallel to the electric field E(sub 0) and metal disk parallel or perpendicular to E(sub 0).
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 1995
 Bibcode:
 1995STIN...9617201K
 Keywords:

 Cavity Resonators;
 Dielectrics;
 Electromagnetic Fields;
 Ellipsoids;
 Metals;
 Resonant Frequencies;
 Disks (Shapes);
 Electric Moments;
 Magnetic Moments;
 Needles;
 Permeability;
 Permittivity;
 Resonance;
 Spheres;
 Communications and Radar