Single-fed circularly polarized dielectric resonator antenna using a uniaxial anisotropic material

A Dielectric Resonator Antenna operating in circular polarization is presented. The proposed antenna is formed by a uniaxial anisotropic dielectric and a ground plane. The optimization of the permittivity tensor and antenna dimensions is performed both theoretically and numerically using an Eigen mode analysis in Ansys HFSS. A good agreement is obtained for the resonant frequencies and quality factors of the different modes. The uniaxial anisotropic DRA radiates two degenerate orthogonal modes, TE
111
^x
and TE
111
^y
, with equal amplitudes and 90° phase difference in order to achieve circular polarization. An impedance bandwidth of 9.8% is accomplished and a broadside radiation pattern with left-hand circular polarization (LHCP) is achieved in simulation. Furthermore, an Axial Ratio (AR) of 0.06 dB at 2.45 GHz and a 3-dB AR bandwidth of 2.04% are obtained. The maximum simulated directivity is equal to 6.56 dBi.