Radio system architecture for a UHF frequency-multiplexed phased-array pico-satellite ground station

Abstract

Recent years have seen a surge in low-Earth-orbit (LEO) small-satellite activity along with a corresponding demand for agile, low-cost ground stations (GSs). Building on this momentum, the University of Malta’s (UM) satellite efforts through the Astrionics Research Group’s ASTREA project aim to conduct in-orbit validation, including testing of materials and electronic components. Drawing on these efforts, this dissertation surveys a frequency-multiplexed phased-array (FMPA) GS for ultra-high-frequency (UHF) P-band satellite links, targeting affordability by using commercial off-the-shelf (COTS) components. To date, more than one thousand five hundred nano-satellites operate in the UHF band, remaining the most utilised choice for launched operations. Presently, the GS configuration requires sixty-four coaxial cable runs beneath the icosahedral geodesic-dome phased-array antenna (GDPAA). Frequency-division multiplexing (FDM) in the FMPA architecture collapses these to two, enabling a compact GS stack with a full complement of usable antenna elements (AEs) and reduced maintenance effort. This study frames and evaluates five candidate architectures, then shortlists two that apply AE-level phasing for beamforming and beam steering, either in software or hardware, culminating in a system (HardwarePS1) enabling multibeam, bidirectional operation. At the target 435 MHz, results confirm feasibility by exceeding ASTREA mission requirements, with the uplink budget yielding a 14.2 dB margin using two GDPAA planar faces, and the downlink achieves −124.9 dBm noise floor through a cascaded noise figure (NF) equivalent to approximately 576 K system noise temperature, delivering a 6.2 dB link margin. End-to-end MATLAB Simulink RF Blockset simulations, including device nonidealities across both signal chains and a 290 K thermal white-noise model, corroborate the operating point to nearly −59 dBc at the desired frequency. From a cost perspective, the baseline bill of materials (BoM) costs roughly €10,500, excluding printed circuit board (PCB) fabrication, while still maintaining the low-cost objective relative to phased-array alternatives. Finally, this work proposes the first reported FMPA uplink and end-to-end UHF operation with hardware-based phasing, indicating a credible, scalable path to multi-satellite GS operations aligned with contemporary LEO mission payloads.