The behavior of high frequency tunable dielectric resonator antenna (DRA) with the addition of excess Fe2O3 in Y3Fe5O12 (YIG) formulation

This manuscript discusses the potential of yttrium iron garnet (YIG) with various amounts of Fe₂O₃ excess, as a tunable dielectric resonator antenna. The exploration of YIG’s antenna microwave properties is a key to determine stability of the antenna radiation pattern and frequency shifting. YIG with various amounts of excess Fe₂O₃ is prepared through a mixed oxide powder technique. Through X-ray diffraction analysis, it was found that addition of 5 wt% excess Fe₂O₃ to YIG stoichiometric formulation has depleted YIP phases in YIG ceramics. However, increasing amount of excess Fe₂O₃ in excess of 15 wt% led to increase in the Fe₂O₃ residue in YIG ceramics. The grains observed using high resolution electron microscopy displayed a well-packed structure. The size of the grains became bigger when the percentage of Fe₂O₃ increased to 20 % but accompanied with significant changes in electrical properties. This change has led to a frequency shift from 14.14 to 17.32 GHz, which cover applications within the Ku-band (12.00–18.00 GHz) together with radiation stability. These results imply that inclusion of excess Fe₂O₃ can be used for tunable DRA.