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

We present two methods for measuring the noise temperature of a differential input single-ended output low-noise amplifier (DISO LNA) connected to an antenna. The first method is the 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.