0.3-to-1.5-GHz LNA with Wideband Noise and Power Matching for Radio Astronomy

2025/09/21 by Lai, Mark, MacKay, Vincent, Wulf, Dallas +2
#FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM)

paper · doi:10.48550/arxiv.2509.17242

Abstract

This paper presents a low-noise amplifier (LNA) that was developed for a new radio telescope comprised of 512 parabolic dish antennas. The LNA closely interfaces to a custom-made antenna feed with an impedance co-designed to provide noise matching over a 5:1 bandwidth. Additionally, a method of broadband noise and power matching that allows the input impedance to be controlled independently from the optimum signal-source impedance to achieve minimum noise is also discussed. When measured in a 50-Ωsystem, the LNA exhibits a return loss (RL) of > 8 dB between 0.32 to 1.5 GHz, S21 of 32 dB ± 1.2 dB, IP1dB > -37 dBm, and IIP3 > -20 dBm. Noise parameter measurements show Tmin ≈ 13 ± 4K and noise temperatures T50Ω ≈ 18 ± 6K between 0.5 to 1.4 GHz.

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