A dual-channel cooled GaAsFET receiver for the Dominion Radio Astrophysical Observatory 26-metre radio telescope covering 1.35 to 1.75 GHz

Author

Walker, G. ; Vaneldik, J.F. ; Routledge, D. ; Landecker, Thomas L. ; Galt, J.A.

Author_Institution

Dept. of Electr. Eng., Alberta Univ., Edmonton, Alta., Canada

Volume

13

Issue

1

fYear

1988

Firstpage

3

Lastpage

7

Abstract

A low-noise receiver for a radio telescope is described. Two identical three-stage GaAsFET amplifiers were built which give excess noise temperatures of less than 28 K with at least 34 dB gain between 1.35 and 1.75 GHz when operated at a physical temperature of 12 K. This noise temperature is measured at the cryostat input connectors. The physical temperature is maintained by a closed cycle helium refrigerator. Source-inductance feedback is used to allow optimum noise performance combined with good input match. Return loss is better than 15 dB across the band. Construction details of the amplifiers and their mounting in the cryostat are provided. Sample observational results are presented.

Keywords

III-V semiconductors; astronomical observatories; cryostats; field effect transistor circuits; gallium arsenide; radio receivers; radiotelescopes; solid-state microwave circuits; 1.35 to 1.75 GHz; 12 K; 15 dB; 26 m; 34 dB; 78 K; Dominion Radio Astrophysical Observatory; GaAs; He; III-V semiconductors; UHF; amplifiers; closed cycle helium refrigerator; cryostat input connectors; dual-channel cooled FET receiver; low-noise receiver; noise temperatures; physical temperature; radio telescope; return loss; source inductance feedback; Connectors; Extraterrestrial measurements; Gain; Noise; Receivers; Telescopes; Temperature measurement;

fLanguage

English

Journal_Title

Electrical Engineering Journal, Canadian

Publisher

ieee

ISSN

0700-9216

Type

jour

DOI

10.1109/CEEJ.1988.6592898

Filename

6592898