Wideband Circularly Polarized Dielectric Resonator Antenna With Wide Overlapped Axial-Ratio and Half-Power Beamwidths

Abstract

In the letter, a wideband circularly polarized dielectric resonator antenna (DRA) with wide overlapped axial-ratio and half-power beamwidths is presented. The antenna mainly consists of the irregular rectangular DRA and the surrounded four metal patches. For wideband operation, the DRA is excited by the Z-shaped slotted ground through the L-shaped feeding line. To achieve wide 3-dB axial-ratio beamwidth (ARBW), processes of cutting corners and grooving are used, which generates the irregular DRA. Furthermore, four simple metal patches are loaded around the DRA to widen the half-power beamwidth (HPBW), which also have the moderating role between the 3-dB ARBW and the HPBW. For validation, the DRA with and without the metal patches are fabricated and tested. Results indicate that under the criterions of 10-dB return loss and 3-dB AR, the overlapped bandwidths are 24.19% and 24.9% for the DRA with and without the metal patches, respectively. For the DRA without the metal patches, wide 3-dB ARBWs (> 161°) can be obtained. While when loading the metal patches, the HPBW can be adjusted to be larger than 123°, and the 3-dB ARBWs are within 141° ∼ 164°, which exhibits a wide overlapped beamwidth of more than 123°.