Semi-Resistive Approach for Tightly Coupled Dipole Array Bandwidth Enhancement

Maxence Carvalho,Elias A Alwan,Alexander D Johnson,John L Volakis

doi:10.1109/ojap.2020.3047494

Maxence Carvalho, Elias A Alwan + Show 2 more

Open Access

https://doi.org/10.1109/ojap.2020.3047494

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Abstract

A new approach to enhance the bandwidth of Tightly Coupled Dipole Arrays (TCDA) is presented. The new design achieves the integration of a semi-resistive Frequency Selective Surface network (FSS) composed of a non-resistive low-pass FSS and two resistive band-stop FSSs. The integration of this FSS network within a dual-polarized Tightly Coupled Dipole Array (TCDA) led to an increased impedance bandwidth of 28:1 from 0.20GHz to 5.6GHz. Notably, the use of an FSS superstrate allowed for scanning down to 60° at VSWR $12 \times 12$ array prototype was fabricated and tested to verify the bandwidth and gain of a finite array. The simulated radiation efficiency was demonstrated to be 83%, on average, across the band.

Highlights

T HE GROWING interest for small space communication platforms (CubeSats) with increased data throughput and broad spectrum coverage implies a need for lowprofile UWB arrays capable of more than 10:1 impedance bandwidth [1]–[3]
Wide Angle Impedance Matching (WAIM) layers were introduced with Tightly Coupled Dipole Arrays (TCDA) for greater bandwidth while scanning [8]–[9]
Low-profile TCDA still exhibits less bandwidth as compared to tapered slot arrays unless resistive loading is used the aperture efficiency is reduced [13]

Summary

INTRODUCTION

T HE GROWING interest for small space communication platforms (CubeSats) with increased data throughput and broad spectrum coverage implies a need for lowprofile UWB arrays capable of more than 10:1 impedance bandwidth [1]–[3]. Wide Angle Impedance Matching (WAIM) layers were introduced with TCDAs for greater bandwidth while scanning [8]–[9] These artificial substrate loadings exhibit anisotropy and are essentially paired with connected slot arrays to extend their bandwidth up to an octave [10]–[12]. To further increase TCDA bandwidth, previous designs incorporated uniform resistive FSS These designs exhibited periodic attenuation at ground plane resonance locations and the added bandwidth was achieved by lowering efficiency across the entire frequency range [17]–[21]. The proposed novel semi-resistive FSS network represents an electrically variable ground plane thickness to ensure congruent radiation This is the first TCDA with a 28:1 broadside bandwidth and an average radiation efficiency greater than 83%.

ARRAY AND FSS SUPERSTRATE DESIGN

ARRAY DESIGN AND SIMULATION

Findings

CONCLUSION AND REMARKS