Investigation of crosspolarisation in offset Cassegrain antennas
Abstract
The geometric optics condition for zero crosspolarization in offset Cassegrain antennas is discussed. It is shown that with a feed having perfect pattern symmetry the crosspolar performance of the offset Cassegrain is limited by diffraction. As a result minimum crosspolarization is only achieved at the geometric optics condition when the subreflector diameter is at least 40 wavelengths.
- Publication:
-
Electronics Letters
- Pub Date:
- August 1981
- DOI:
- 10.1049/el:19810412
- Bibcode:
- 1981ElL....17..585B
- Keywords:
-
- Antenna Design;
- Cassegrain Antennas;
- Cross Polarization;
- Geometrical Optics;
- Antenna Feeds;
- Performance Prediction;
- Sidelobe Reduction;
- Subreflectors;
- Communications and Radar