Improved Microstrip Circulator Design by Modified Resonance computations

Microstrip circular disc resonators with pure dielectric or gyrotropic substrates are of some practical interest in the field of MIC´s. To evaluate the resonance frequencies especially of those, realized on ferrimagnetic materials, a new approach was made, giving better accuracy than the commonly used magnetic-wall-model. In this paper we present a brief summary of the theory, some numerical features and several computed resonance frequencies, which agree very well with experimental data.