Resonance Characteristics and Tunability of Calcium Vanadium Garnets as Ferrite Resonator Antennas

The main scope of this work is to employ a Calcium Vanadium Garnets ceramic composite as a ferrite resonator cylindrical antenna and investigate tunability in the presence an external biasing magnetic field. The numerical analysis is carried out via Ansoft's High Frequency Structure Simulator (HFSS™) software package. The antenna is fed through a side coaxial probe whose geometrical configurations are parametrically studied and optimized. The resonance profile of the antenna is characterized and compared to a traditional dielectric resonator antenna. The ferrite resonator antenna displayed two resonance dips rather than that collectively resulted in widening its resonance bandwidth to 1.17 GHz. The paper next discusses the significance of optimizing the length of feeding coaxial probe and its distance from the antenna by explaining to the behavior of the radiation of the structure with respect to the variation of these parameters. The study is concluded by a characterization of the tuning capabilities of the structure in the form of variation in the resonance frequency of the antenna in addition to its bandwidth with respect increasing of the applied external magnetic field intensity. The tunability of each respective parameter was found to be 4.29 MHz/mT and 0.29 MHz/mT.