Single-Fed Circularly Polarized Dielectric Resonator Antenna With an Enhanced Axial Ratio Bandwidth and Enhanced Gain

Son Trinh-Van,Kang-Yoon Lee,Keum Cheol Hwang,Youngoo Yang

doi:10.1109/access.2020.2976780

Abstract

A compact single-fed circularly polarized dielectric resonator antenna (DRA) with an enhanced 3-dB axial ratio bandwidth (ARBW) and gain is proposed. The DRA is implemented by joining a smaller dielectric resonator (DR) to one side wall of a main rectangular DR and is excited by an offset vertical metallic strip. With this configuration, two sets of degenerate orthogonal modes, the TE 111 mode and TE 113 mode, are simultaneously excited to realize wideband circular polarization operation. Furthermore, by removing a small DR portion from the lower corner of the main DR, the boresight gains at higher frequencies are significantly enhanced. An antenna prototype is fabricated and measured to verify the performance of the proposed design. The experimental results illustrate that the proposed antenna achieves a measured 3-dB ARBW of approximately 44.73% (3.68-5.80 GHz) in conjunction with a broad -10 dB impedance bandwidth of 69.66% (2.9-6.0 GHz). The measured boresight gain is found to be 5.49± 0.85 dBic within the passband with a maximum value of 6.34 dBic at 4.7 GHz. Moreover, reasonable agreement between the simulated and measured results is achieved.

Highlights

A dielectric resonator (DR) fabricated with a low-loss and high-permittivity material was implemented for the first time as an antenna by Long et al [1] in 1983
dielectric resonator antenna (DRA) with circularly polarized (CP) radiation are preferred for such systems, as CP antennas, compared to linearly polarized (LP) antennas, are less affected by multipath interference and by misalignment between the transmitting and receiving antennas [4]
In the frequency range of 3.73–5.78 GHz, Antenna II has a slowly varying amplitude ratio (|Ex |/|Ey|) around 1 (0.82–1.28) and a phase difference (PD) ranging from 80◦ to 100◦, leading to a wider CP bandwidth. These results demonstrate that Antenna II achieves a significantly enhanced 3-dB axial ratio bandwidth (ARBW) as compared to Antenna I

Summary

Introduction

A dielectric resonator (DR) fabricated with a low-loss and high-permittivity material was implemented for the first time as an antenna by Long et al [1] in 1983. A small DR portion from the lower corner of the main rectangular DR is removed to increase the radiation from the side walls [21], significantly enhancing the broadside gain at higher frequencies.

Results

Conclusion