A Compact Wideband Dielectric Resonator Antenna With a Meandered Slot Ring and Cavity Backing

We design a compact cavity-backed antenna structure where a dielectric resonator (DR) element is surrounded by a meandered circular slot ring to enhance radiation efficiency. The DR for the antenna is cylindrical in shape, and four degenerate HE 11δ modes are excited and driven by four, quadrature-fed aperture-coupled slots. Such a compact implementation hybridizes operation of the DR with the miniaturized ring as well as the four aperture-coupled slots for circular polarization. Measured realized gain values are greater than 5 dBic from 1.14 to 1.55 GHz defining a bandwidth of more than 30%. In addition, the half-power and 3-dB axial-ratio beamwidths were measured to be more than 100 ° and 200 °, respectively. The proposed design technique to employ such a secondary meandered slot ring may also be useful to improve antenna gain, bandwidth, and efficiency for other antenna and array structures.