Evaluation of a cryogenic coaxial noise source based on the calibration method by single auxiliary transmission line

Abstract

A method to estimate the noise temperature of a noise source by using an auxiliary transmission line (ATL) is proposed and discussed. A cryogenic 7-mm coaxial noise source is developed for verifying the ATL method. The noise temperature is determined from the parameters directly measured by a radiometer and the available power ratio of the transmission line measured by a vector network analyzer using the ATL. The experimental results in the frequency range of 8–12 GHz show a validity of the method for determining noise temperature.