0.3–1.5-GHz LNA With Wideband Noise and Power Matching for Radio Astronomy

This letter 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 (BW). Additionally, a method of broadband noise and power matching that allows the input impedance to be controlled independent of the optimum signal-source impedance to achieve minimum noise is also discussed. When measured in a 50-
$\Omega $
system, the LNA exhibits a return loss (RL) of
$>$
8 dB between 0.32 and 1.5 GHz, S21 of 32 ± 1.2 dB, IP1dB−37 dBm, and IIP3−20 dBm. Noise parameter measurements show
$T_{\text {min}} \approx 13 \pm $
4 K and noise temperatures
$T_{50\,\Omega } \approx 18 \pm $
6 K between 0.5 and 1.4 GHz.