Microwave Compact Antenna Test Range (CATR)

The Microwave CATR reflector is a parabolic single offset antenna of 3 metres in diameter and constructed from 18 high precision panels. These panels were developed and manufactured at the Rutherford Appleton Laboratories, UK, for the James Clerk Maxwell Telescope. The individual panels have a measured average r.m.s. surface accuracy of between 8 and 15 microns. Each panel has three micrometer adjustable mounting points and are individually aligned using the two theodolite method. At present the overall surface has an r.m.s accuracy of about 90 microns. The quiet zone is 1.0m in diameter and has ±0.5 dB ripple and 5 deg phase taper.

The facility has been constructed with the financial support of British Aerospace Space Systems Limited for the RF testing of AMSU-B a satellite-borne millimetrewave radiometer funded by the UK Meteorological Office. Laboratory infrastructure has been provided mainly by SERC (now EPSRC).

The turntable system is mounted on rails providing down range movement and has a hydraulic platform to provide height adjustment along with a precision cross slide providing transverse horizontal movement. The Orbit AL 4373-1 azimuth over elevation turntable can take a maximum load of over one ton with positional accuracy on both axes of 0.005 degrees. Turntable control is via an Orbit AL 4706 controller linked to our measurement software.

The range has been operated successfully down to 5GHz and up to 60GHz.

Press on the pictures to see CATR Schematics