VHF/UHF Ultrawideband Tightly Coupled Dipole Array for CubeSats

Vignesh Manohar,John L Volakis,Satheesh Bojja Venkatakrishnan,Shubhendu Bhardwaj

doi:10.1109/ojap.2021.3083938

Vignesh Manohar, John L Volakis + Show 2 more

Open Access

https://doi.org/10.1109/ojap.2021.3083938

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Abstract

To date, CubeSat radars and imagers have been limited to operations beyond S-band due to the challenges associated with the design of wideband, compact, low-frequency antennas. Concurrently, the frequencies at VHF/UHF bands can image through clouds and foliage, and are very attractive for ice, water and biomass sensing. There is thus a need to develop wideband antennas that can operate at VHF/UHF bands which are low cost, light-weight, and packable. In this paper, we present a CubeSat deployable Tightly Coupled Dipole Array (TCDA) that achieves VSWR<; 3 from 80 MHz - 600 MHz, and VSWR<; 4 from 65 MHz - 600 MHz. While the array itself is 1.2 m in length, 10 cm in width and 1.5 mm in thickness, it can be folded and stowed in a compact volume of 0.40U. We detail the design of the array, demonstrate the folding mechanism, and validate its performance through measurements.

Highlights

C UBESATS represent a class of miniaturized satellites that can weigh as little as 1.33 kg and occupy a volume of 10 × 10 × 10 cm3
While Synthetic Aperture Radar (SAR) techniques can be used to generate a large aperture in the direction of motion of the satellite, reasonable resolution in the cross-track at low frequencies can only be achieved through a constellation of CubeSats [1], [2]
To conform to the mechanical constraints of CubeSats, this paper describes the design of a linear version of the Tightly Coupled Dipole Array (TCDA)

Summary

INTRODUCTION

C UBESATS represent a class of miniaturized satellites that can weigh as little as 1.33 kg and occupy a volume of 10 × 10 × 10 cm (commonly referred to as 1U). Reflector antennas have already demonstrated their potential for CubeSat missions at S-band and above [4], [20] They become unmanageably large at VHF/UHF frequencies. It should be noted that only the center elements of the array are excited to achieve the wide bandwidth The differential feed employed by our design enables high dynamic range and low-noise operations [28] This allows the antenna to directly interface with differential amplifiers without the need for a balun, thereby reducing hardware requirements aboard the CubeSat. B.

MEASUREMENT RESULTS

CONCLUSION