DocumentCode :
292549
Title :
Noise temperature contribution of a dichroic plate in a beam-waveguide antenna system
Author :
Otoshi, T.Y. ; France, M.M.
Author_Institution :
Jet Propulsion Lab., California Inst. of Technol., Pasadena, CA, USA
Volume :
1
fYear :
1994
fDate :
20-24 June 1994
Firstpage :
262
Abstract :
A 34-m-diameter antenna, built for NASA/JPL, utilizes a beam-waveguide (BWG) design. The BWG antenna performances at three different focal points were previously reported by Bathker et al. (1992). The ellipsoid in the subterranean room has since been made rotatable so that numerous feed systems can be installed in a circular perimeter around the ellipsoid and operated from their own individual f3 positions. One of the recently installed front-end systems at a new f3 position is the S/X system, which permits simultaneous operation of S-and X-band downlink. Measurements of the X-band system showed that the dichroic plate noise temperature contribution was 18 K compared to a predicted value of 1.5 K. It was later discovered that if a dichroic plate is installed in a BWG antenna environment, high noise temperatures can result if the receive system passband is greater than the passband for which the plate was designed. A method is presented for accurately calculating dichroic plate noise temperature for these conditions.<>
Keywords :
antenna testing; microwave antennas; noise; reflector antenna feeds; waveguide antennas; BWG antenna performances; S-band downlink; S/X system; X-band downlink; beam-waveguide antenna system; dichroic plate; ellipsoid; feed systems; focal points; front-end systems; noise temperature; receive system passband; subterranean room; Antenna measurements; Downlink; Ellipsoids; Feeds; NASA; Noise measurement; Passband; Receiving antennas; Temperature; Working environment noise;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Antennas and Propagation Society International Symposium, 1994. AP-S. Digest
Conference_Location :
Seattle, WA, USA
Print_ISBN :
0-7803-2009-3
Type :
conf
DOI :
10.1109/APS.1994.407762
Filename :
407762
Link To Document :
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