Wideband Circularly Polarized Rectangular Dielectric Resonator Antennas Using Square-Shaped Slots

Abstract

Two wideband single fed circularly polarized (CP) rectangular dielectric resonator antennas (DRAs) comprising square-shaped slots are proposed. Initially, two wideband linearly polarized DRAs are designed with high aspect ratio to simultaneously excite and merge two resonant modes, <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm TE}_{{111}}$</tex></formula> and <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm TE}_{{113}}$</tex></formula> . Then, CP is obtained by the technique of perturbation in the form of four and two square slots along the diagonal. The slots excite two orthogonal modes with same magnitude and quadrature in phase. Two antenna prototypes are experimentally verified. The measured impedance bandwidths are 48% (4.7–7.7 GHz) and 41% (4.6–7 GHz) in conjunction with the 3-dB axial-ratio bandwidth of 11.5% (5.7–6.4 GHz) and 24% (4.7–6 GHz).