Dual Circularly Polarized Hybrid Dielectric Resonant Antenna Based on Cross Slot Feeding

A dual circularly polarized hybrid dielectric resonator antenna with wide bandwidth is proposed in this letter. The dielectric resonator is placed on top of a cross slot feeding structure and it is made of a rectangular microwave dielectric ceramics (Al
2
O
3
) with a dielectric constant of 9.2. In order to obtain a wider impedance bandwidth and 3dB axial ratio bandwidth, a windmill shaped patch is inserted into the dielectric resonator. The broadband characteristics of the antenna are formed by the superposition of three circular polarization modes, which are provided by the cross slot at the bottom, high dielectric constant microwave dielectric ceramic materials, and metal patches of inserted ceramic dielectric resonators. The three circular polarization modes are located in close frequency ranges and can be simultaneously excited within a certain frequency range. Unlike traditional dual circularly polarized antennas, the antenna designed in this paper does not require 3dB hybrid coupler to generate a±90
^◦
phase difference or consider the coupling of the two ports. The two ports of the antenna work in time-sharing, and circularly polarized radiation is achieved by exciting two pairs of orthogonal degenerate modes. When feeding one of the two ports, the antenna can radiate left-handed circularly polarized waves or right-handed circularly polarized waves. The S
11
of the antenna is less than −10dB at 7.0– 11.0GHz, and the axial ratio bandwidth (AR < 3dB) of the antenna is 28.9% (8.0–10.6GHz). The axial bandwidth and impedance bandwidth of the antenna overlap, meaning that the frequency range of the antenna below 3dB is the operating range of the antenna. The gain of the antenna near the center frequency of 9.0GHz is 7.2dBi. The antenna designed in this paper has compact structure and excellent radiation performance, which provides a new design scheme for wireless communication system.