Wideband circularly polarized half-split embedded cylindrical DRA excited with slotted patch for WLAN/Wi-MAX applications

In this paper, a wideband circularly polarized half- split embedded cylindrical dielectric resonator antenna (CDRA) with varying permittivity in the radial direction is developed for the WLAN/Wi-MAX applications. Proposed antenna consists of half-split (HS) cylindrical dielectric resonator (CDR) having two different layers of permittivity in the radial direction, a modified CPW-feed (a signal line, rectangular and slotted patch) and the ground plane. Circular polarization is procured by exciting orthogonal mode in half-split CDR through modified CPW-feed. TM11Ô mode is excited inside the HS-CDRA and confirmed by the rotation of electric field. Designed antenna radiates right- hand circular polarization field in the broadside direction and stronger than its counterpart left-hand circular polarization by -22.67 dB over the entire working band. The proposed antenna shows the usable bandwidth of 12.62% at the center frequency of 5.15 GHz, where both Sii < -10 dB input impedance bandwidth and AR < 3 dB bandwidth falls 4.83-5.62 GHz range. In addition, maximum gain and radiation efficiency in broadside direction are found to be 1.99 dBic and 96.57% respectively.