Compact and Wideband Circularly Polarized Quadrature Rectangular Dielectric Resonator Antenna

Compact and wideband Circularly Polarized (CP) Quadrature Rectangular Dielectric Resonator Antenna (Q-RDRA) is designed and proposed using coaxial feed. The square shaped slots filled with air $\epsilon_{r}=1$ are introduced to obtain wide impedance bandwidth by reducing effective dielectric constant. The edge grounding technique is used to miniaturize RDRA to the size 0.2 $\lambda_{c}\times 0.2\ \lambda_{c}\times 0.2\ \lambda_{c}$ at centre frequency of 5.4 GHz. CP fields are obtained by optimizing feed location at an offset along x and y axis to excite $TE_{111}^{x}$ like and $TE_{111}^{y}$ like orthogonal modes. The proposed CP Q-RDRA provides wider 3-dB axial ratio bandwidth (ARBW) $ARBW\leq 3dB$ of 42% (4.4 – 6.8 GHz),impedance bandwidth $S_{11}\leq-10dB$ of 72% (3.4 – 7.3 GHz) respectively. The proposed structure offers LHCP gain of more than 6 dB and radiation efficiency of more than 95% in the complete frequency range of operation. Proposed CP antenna is applicable for C-band, Wi-MAX, WLAN applications.