A Circularly Polarized Antenna by Using Rotated-Stair Dielectric Resonator

In this letter, a wideband compact circularly polarized (CP) dielectric resonator antenna (DRA) is proposed. This antenna consists of two rectangular dielectric layers that are stacked with a rotation angle φ relative to its adjacent bottom layer. The antenna is excited by an aperture coupled through a slot cutting on the ground plane. The rotated-stair configuration of DRA contributes dual broadside CP radiating modes and results in a noticeable enhancement in the axial ratio (AR) bandwidth. The proposed antenna achieves 31% impedance bandwidth and 18.2% AR bandwidth. The average gain within the AR bandwidth is 4.5 dBi with less than 0.5-dB variation. Moreover, the proposed dielectric resonator antenna has a low-profile structure. This work demonstrates a CP bandwidth broadening technique for the DRA. The potential applications of the antenna are 5G Wi-Fi and satellite communication systems.