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.