Citation
Abstract
A cryogenically cooled, low-noise Field Effect Transistor (FET) amplifier assembly for use at 2.2 to 2.3 GHz has been developed for the DSN to meet the requirements of a Very Long Baseline Interferometry (VLBI) upgrade. An amplifier assembly was developed at JPL that uses a commercial closed-cycle helium refrigerator (CCR) to coola FET amplifier to an operating temperature of 15 K. A cooled probe waveguide-to-coaxial transition similar to that used in the R&D Ultra-Low-Noise S-band Traveling Wave Maser (TWM) is used to minimize input line losses. Typical performance includes an input flange equivalent noise contribution of 14.5 K, a gain slope of less than 0.05 aB/MHz across a bandwidth of 2.2 to 2.3 GHz, an input VSWR of 1.5:1 at 2.25 GHz, and an insertion gain of 45 + 1 dB across the bandwidth of 2.2 to 2.3 GHz. Three 2.3-GHz FET/ CCR assemblies were delivered to the DSN in the spring of 1987.
Details
- Volume
- 42-93
- Published
- May 15, 1988
- Pages
- 199–206
- File Size
- 293.1 KB