Title :
Minimise pattern degradation when subreflector vertex shaping is used to improve feed match
Author :
Sprey, M.A. ; Bird, T.S.
Author_Institution :
Div. of Radiophys., CSIRO, Epping, NSW, Australia
fDate :
4/25/1996 12:00:00 AM
Abstract :
A knob placed at the vertex of a subreflector to reduce subreflector mismatch in a shaped Cassegrain antenna can significantly degrade the radiation pattern and reduce efficiency. A practical procedure is described to lessen these effects. Best results are obtained using a cosine-squared-shaped knob, keeping a low knob height and knob base within the feed blockage region. The importance of simultaneously optimising for return loss, antenna efficiency and sidelobe level is emphasised
Keywords :
antenna radiation patterns; microwave antennas; reflector antenna feeds; satellite antennas; antenna efficiency; cosine-squared-shaped knob; earth-station antennas; feed blockage region; feed match improvement; pattern degradation minimisation; return loss; shaped Cassegrain antenna; sidelobe level; subreflector vertex shaping;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19960547
