Measurements of the sideband conversion gain ratio of a millimeter-wave heterodyne sub-harmonic mixer using a fourier transform spectrometer

Abstract

A Fourier transform spectrometer, based on a Martin-Puplett polarisation rotation interferometer and using broad-band blackbody noise sources, has been used to study the sideband response i.e., conversion gain, of a room temperature Schottky diode sub-harmonic mixer operating at 300 GHz. The technique enables the response of the mixer to be characterised and preferentially tuned to one sideband, thereby improving the rejection of unwanted spectral components which can be present in the mixer image sideband.