YIG Matrix Based Multiband Magneto-Dielectric Cylindrical Resonator Antenna

Abstract

A multiband magneto-dielectric resonator antenna with cylindrical geometry is proposed in this paper. The resonator is composed of yttrium iron garnet (YIG) with chemical composition Y₃Fe₂(FeO₄)₃. The final structure is built on a low-cost FR4 dielectric substrate. With only one resonator, the antenna is able to resonate in three distinct controlled frequency bands. These are the three propagation modes HEM_11δ, TE_01δ, and TM_01δ, which are possible to be independently controlled at each input port of the resonator antenna. The resonator’s port was suitable designed to feed specific modes of the antenna using microstrip lines placed judiciously to excite each mode. Analytic, numerical, and experimental studies were performed and, after optimization, the final antenna design was obtained. The obtained simulated and measured S-parameters results are below -10 dB at the resonance frequencies 5.75 GHz, 6.86 GHz, and 8.37 GHz. The corresponding measured bandwidths are 370 MHz, 120 MHz, and 1060 MHz, respectively. The antenna has a total size of 32.5 × 32.5 × 8.35 mm³. Measured radiation patterns and gain are also presented and show good agreement when compared to simulated results.

Index Terms
magneto-dielectric material; multiports; resonator antenna; YIG