title: Low noise, 0.4-3 GHz cryogenic receiver for radio astronomy.
abstract: We present the design and measurement of a radio telescope receiver front end cooled to 100 K physical temperature, and working over 400 MHz to 3 GHz frequency band. The system uses a frequency independent feed developed for operation as a feed for parabola using sinuous elements and integrated with an ultra-wideband low noise amplifier. The ambient temperature system is tested on the 43 m radio telescope in Green Bank, WV and the system verification results on the sky are presented. The cryogenic receiver is developed using a Stirling cycle, one stage cryocooler. The measured far field patterns and the system noise less than 80 K over a 5:1 bandwidth are presented.
authors.affiliation: Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, Virginia 22903, USA.
authors.forename: R
authors.initials: R
authors.lastname: Gawande
authors.affiliation: National Radio Astronomy Observatory, Charlottesville, Virginia 22903, USA.
authors.forename: R
authors.initials: R
authors.lastname: Bradley
authors.affiliation: National Radio Astronomy Observatory, Green Bank, West Virginia 24944, USA.
authors.forename: G
authors.initials: G
authors.lastname: Langston