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

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 surrounding 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 has a 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 criteria 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 degrees) can be obtained. When loading the metal patches, the HPBW can be adjusted to be larger than 123 degrees, and the 3 dB ARBWs are within 141 degrees similar to 164 degrees, which exhibits a wide overlapped beamwidth of more than 123 degrees.