Cryogenically Cooled Millimetre-Wave Front Ends for the Australia Telescope

Cryogenically cooled receiver systems covering three millimetre-wave observing bands have been installed on the Australia Telescope National Facility Compact Array (ATCA), situated near Narrabri in northern New South Wales, Australia. The ATCA consists of six 22-metre dish antennas capable of operating at frequencies in excess of 115 GHz. Millimetre-wave receiver systems covering the frequency ranges 16 to 26 GHz and 85 to 105 GHz have been upgraded with the installation of a receiver system covering the 30 to 50 GHz band. We will describe the final receiver system and present the results of tests on these receiver systems.