Evaluation of Resonant Modes in Magneto-dielectric Circular Patch Antenna

This study evaluates the resonant modes of a magneto-dielectric (MD) circular patch antenna incorporated by a ferrite material without external magnetic bias. The ferrite material used is Yttrium Iron Garnet (YIG), which has a circular shape with the dimensions of 18.1 mm in diameter and 4.7 mm in thickness. This ferrite material is incorporated in the host dielectric substrate to realize an MD circular patch antenna. Meanwhile, the host dielectric material employs an FR-4 epoxy substrate with the thickness of 4.8 mm. The results shows that the MD circular patch antenna operates at the resonant frequency of 4.67 GHz, shifted from the fundamental frequency of 4.34 GHz, which is observed in the conventional circular patch antenna. Investigation on the distributions of electric field and surface current density indicates that the resonant frequency of MD circular patch antenna is closely corresponded to higher-order resonant modes.