Low noise GaAs FET dual channel front end
Abstract
A stable low-noise L-band front end has been designed for use on the Arecibo telescope which minimizes effects external to the amplifier. The device uses GaAs FET amplifiers, L-band isolators operating at cryogenic temperatures, and a 'cold probe' borrowed from experience gained in the S band maser development. The dual channel receiver, which has been in operation at the Arecibo facility since 1980, is packaged within a single vacuum dewar and cooled by a standard cryogenic refrigeration system. A separate package attached to the dewar provides GaAs FET bias supplies, and metering and calibration signals. Receiver equivalent noise temperature at the waveguide flange is measured to be less than 15 K across the band from 1300 to 1500 MHz; system temperature (including antenna) is calculated to be 40 K, in which noise contribution of the antenna has been estimated at 20 K and sky noise contribution is about 5 K.
- Publication:
-
Microwave Journal
- Pub Date:
- May 1982
- Bibcode:
- 1982MiJo...25..153P
- Keywords:
-
- Amplifier Design;
- Field Effect Transistors;
- Gallium Arsenides;
- Low Noise;
- Microwave Amplifiers;
- Calibrating;
- Cooling Systems;
- Cryogenics;
- Noise Temperature;
- Transistor Amplifiers;
- Waveguides;
- Electronics and Electrical Engineering