Cold-Source Noise Measurement of a Differential Input Single-Ended Output Low-Noise Amplifier Connected to a Low-Frequency Radio Astronomy Antenna

TL;DR

This paper introduces two practical methods for measuring the noise temperature of a differential input single-ended output low-noise amplifier connected to a radio astronomy antenna, facilitating accurate noise characterization.

Contribution

It presents novel measurement techniques, including an anechoic chamber test and a low-cost noise parameter extraction method, for DISO LNAs in radio astronomy applications.

Findings

Successful application to Murchison Widefield Array LNA and antenna

Effective noise temperature measurement in realistic conditions

Validation of noise parameter extraction method

Abstract

We present two methods for measuring the noise temperature of a differential input single-ended output (DISO) Low-Noise Amplifier (LNA) connected to an antenna. The first method is direct measurement of the DISO LNA and antenna in an anechoic chamber at ambient temperature. The second is a simple and low-cost noise parameter extraction of the DISO device using a coaxial long cable. The reconstruction of the DISO noise parameter from the noise wave measurements of the DISO LNA with one terminated input port is discussed in detail. We successfully applied these methods to the Murchison Widefield Array LNA and antenna.