The effects of subreflector diffraction on the aperture efficiency of a conventional Cassegrain antenna - An analytical approach
Abstract
An asymptotic theory is presented with which the reduction in aperture efficiency caused by diffraction from a subreflector edge can be calculated for any dual-reflector system. The theory is applied to conventional Cassegrain antennas, for which approximate analytical efficiency formulas are derived. These formulas show that subreflector diffraction may represent a significant efficiency loss even for subreflector diameters as large as 20 wavelengths. The formulas are used to obtain an optimum subreflector size which represents the best trade-off between losses due to subreflector diffraction and geometrical shadowing.
- Publication:
-
IEEE Transactions on Antennas and Propagation
- Pub Date:
- November 1983
- DOI:
- 10.1109/TAP.1983.1143161
- Bibcode:
- 1983ITAP...31..903K
- Keywords:
-
- Antenna Design;
- Cassegrain Antennas;
- Subreflectors;
- Transmission Efficiency;
- Two Reflector Antennas;
- Wave Diffraction;
- Apertures;
- Asymptotic Methods;
- Design Analysis;
- Geometrical Optics;
- Microwave Antennas;
- Communications and Radar