2 × 2 Slot Spiral Cavity-Backed Antenna Array Fed by Printed Gap Waveguide

Elham Baghernia,Abdel Razik Sebak,Mohamed Mamdouh M Ali

doi:10.1109/access.2020.3024564

Elham Baghernia, Abdel Razik Sebak + Show 1 more

Open Access

https://doi.org/10.1109/access.2020.3024564

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Abstract

A wideband circularly polarized slot spiral antenna array excited by a printed gap waveguide (PGW) feeding network is presented in this paper. The equiangular slot spiral is etched on the top wall of the substrate integrated cavity (SIC) in which TE120 mode is excited. Due to excitation of this mode, electric field distribution in two halves of the substrate integrated cavity is the same in magnitude and 180° out of phase. Therefore, the slot spirals are fed differentially by this cavity and become independent of the complex vertical balun structures. The sequential feeding is implemented by PGW technology, which results in high efficiency of the array structure. Moreover, by employing SIC and PGW technologies, this antenna is compatible with low cost printed circuit board (PCB) technology. A prototype of the proposed antenna was fabricated and measured to evaluate the antenna performance. The fabricated antenna array shows the -10 dB impedance bandwidth of 23.7% and the 3 dB AR of 22.5% with the measured RHCP gain of 12.3 dBic.

Highlights

The growing demand for high data rate in wireless communication systems has built a significant momentum toward the fifth generation (5G) communications as there are more uncongested frequency bands compared to sub 6 GHz band
The implementation of circular polarization (CP) antenna arrays with state-of-the-art guiding structures such as printed gap waveguide (PGW) is an essential step to enhance the efficiency of future communication systems
The presented array is low profile as the radiating elements are etched on the substrate integrated cavity (SIC) and no separate balun structure used to differentially excite the slot spiral arms

Summary

INTRODUCTION

The growing demand for high data rate in wireless communication systems has built a significant momentum toward the fifth generation (5G) communications as there are more uncongested frequency bands compared to sub 6 GHz band. E. Baghernia et al.: 2 × 2 Slot Spiral Cavity-Backed Antenna Array Fed by PGW are advantageous over spiral antennas as they can be etched on a metal surface of the same substrate with the feeding and do not require an extra layer to contain the radiating elements [13]. There are few papers about slot spiral antennas at mm-wave frequencies, which might be due to the complicity of the existing feeding procedures. A 2 × 2 cavity-backed slot spiral antenna array fed by PGW for mm-wave applications is presented. The presented array is low profile as the radiating elements are etched on the SIC and no separate balun structure used to differentially excite the slot spiral arms. For the two-arm spiral antenna, the balanced mode is excited if the arms have the same amplitude and 180◦ phase shift [20]

CAVITY EXCITATION

FABRICATION AND MEASUREMENT

Findings

CONCLUSION