Tunable microwave ferrite filter for receiving-transmitting mobile communications systems

The development of a tunable microwave filter using YIG-ferrite resonators in the form of cylinders is described. A model for calculating a tunable WFR (waveguide-ferrite resonator) with E_01δ mode is proposed. The model makes it possible to predict the main electric parameters of the WFR. The cascading of the WFR allows magnetic-field-tunable bandpass filters to be realized. It is shown that the control of the bandpass and that of the filter´s tuning frequency can be obtained depending on the geometry of the filter structure. Experiments have shown that the application of polycrystalline ferrite Y₃Fe₅O₁₂ makes it possible to increase the microwave power handling level in the proposed construction of the filter by three orders of magnitude