The CASS Engineering Front End Group

Led by Mark Bowen, this group is composed of engineers and technicians that, as a group, has the capabilities to design and construct both room temperature and cryogenic radioastronomy front ends. The CASS workshop staff contribute the essential skills and specialised expertise to make the technical staff's designs a reality. High precision machining of large and small scale structures using both computer controlled and manually operated machines is complemented by more conventional 'hands on' precision craftsmanship including sheet metal work and all forms of welding/brazing.

The Front End Group's expertise lies principally in the areas of passive microwave devices, InP MMICs , HEMT LNAs, cryogenics, signal frequency and IF frequency processing (microstrip circuits), control and monitor electronics, 3D EM modelling, assembly of RF and DC electronics including clean room techniques, PCB assembly, cryogenics (design, systems, servicing), metal surface treatment (cleaning, anodising, high precision plating) and quasioptic design.

Front ends are constructed for ATNF antennas as well as overseas observatories. The Arecibo Observatory has benefitted from the 7 beam receiver designed and fabricated by the CASS Front End Group and shown here.

An upgrade in 2007/2008 completed a program to equip the Compact Array antennas with the latest in millimetre wave technology. This 7mm Upgrade project enabled the already operational 3mm / 12mm receivers to have 7mm capability. In frequency terms, a 30-50GHz capability has been added to the single package that is already capable of observations at 18-26GHz and 85-105GHz.

Current major projects include:

  • An upgrade to the Compact Array's 20/13cm and 6/3cm front ends. The successful development of new 1-3 GHz and 4-12 GHz low noise amplifiers and a 4-12 GHz orthomode transducer all of which can be retrofitted to the existing receivers will combine with the Compact Array Broadband Backend project to deliver a powerful new instrument for cm observations. January 2011 saw all Compact Array antennas equipped with the new 1-3 GHz (16 cm) receivers. 4-12 GHz receivers were rolled out to antennas through 2012/13 with all antennas being fully outfitted in March 2013. Fabrication of a spare receiver by June 2013 ensured a full suite was available.
Arecibo 7 beam receiver