Tunable dielectric resonator with circumferentially magnetized ferrite disks
Electronically tunable dielectric resonator containing circumferentially magnetized ferrite elements has been investigated. The structure of the resonator has been analysed to obtain the optimal parameters. The resonator was constructed whose resonant frequencies can be switched by short current pulses between two stable values that differ in frequency up to 25 MHz with Q-factor value about 4200.
Optimization of Spurious Response in Dielectric Resonator Tunable Filters
Methods of tunable filters spurious response improvement are described. Dielectric resonator based filters with ferrite elements suffer from spurious resonances located close to the useful passband. Optimization of the resonator structure as well as application of TEM resonators leads to significant improvement. Design methods and measured results are provided.
Determination of Loaded, Unloaded, and External Quality Factors of a Dielectric Resonator Coupled to a Microstrip Line
In the case of a dielectric resonator coupled to a microstrip line, the relations for the determination of unloaded, loaded, and external quality factors, in terms of directly measurable reflection or transmission coefficient at the resonant frequency, have been derived and represented on the corresponding vectorial and scalar planes. Construction of a linear frequency scale and a graphical method to accurately determine the unloaded Q from the loaded Q measurement presented.