Microwave signal processing for a cryogenic gravitational radiation antenna with a noncontacting readout

Abstract
A modified version of the microwave signal processing system for the 1.5 tonne niobium bar gravitational radiation antenna at the University of Western Australia has been developed and tested during preparations for long-term observation. Among the new features of the system are a noncontacting microwave coupling to the motion transducer, cryogenic low-noise amplification, and automatic carrier suppression with improved long-term stability.