A Broadband High-Gain Circularly Polarized Wide Beam Scanning Leaky-Wave Antenna

Yiming Zhang,Sailing He,Chenyang Meng,Yuxin Lin,Erik Forsberg,Yuan Zhang,Hui Liu

doi:10.1109/access.2020.3021201

Abstract

A new type of broadband circularly polarized leaky-wave antenna (LWA) with high-gain based on a corrugated substrate integrated waveguide (CSIW) structure is proposed and investigated. The CSIW structure that employs open-circuit stubs to replace metallic vias has the advantages of low-cost and easy fabrication as compared to conventional substrate integrated waveguides. Each unit-cell of the proposed LWA consists of two quarter-wavelength microstrip lines and a half-mode CSIW cell with three open-circuit stubs. Two M-shaped slots etched on the half-mode CSIW cell enables the generation of circularly polarized (CP) radiation. The full LWA, which consists of thirteen matched unit-cells cascaded along the direction of propagation enables continuous backward to forward beam scanning. The properties of the CSIW structure, including impedance matching and phase constant, are analyzed by Bloch impedance and dispersion simulations and the influence of the dimensions of the open-circuit stubs on the CP LWA performance is also investigated. A protype of the proposed LWA is fabricated and characterized. The measured results indicate that the proposed CSIW LWA has a high peak gain (9.3-12.5 dBi) throughout a large beam-scanning angle range from -28° to +25°, and the impedance bandwidth and 3-dB axial ratio (AR) bandwidth are over 40% covering the full $\textit {Ka}$ -band.

Highlights

Leaky-wave antennas (LWAs) are wave-guiding structures in which a travelling wave radiates through energy leakage along the entirety of the structure [1], [2]
A circularly polarized (CP) LWA based on a corrugated substrate integrated waveguide (CSIW), which utilized two compound slot pair arrays etched on the top of the antenna to achieve broadside radiation and good axial ration (AR) in the main beam direction, has been proposed [14]
In this article we propose a broadband CSIW CP LWA with M-shaped slots based on a CSIW with high gain and wide beam scanning ability

Summary

Introduction

Leaky-wave antennas (LWAs) are wave-guiding structures in which a travelling wave radiates through energy leakage along the entirety of the structure [1], [2]. A circularly polarized (CP) LWA based on a CSIW, which utilized two compound slot pair arrays etched on the top of the antenna to achieve broadside radiation and good axial ration (AR) in the main beam direction, has been proposed [14].

Results

Conclusion