Co-polar and cross-polar diffraction images in the focal plane of paraboloidal reflectors - A comparison between linear and circular polarization
Abstract
Equations for the co-polar and cross-polar fields in the focal plane of paraboloidal reflectors when excited by a plane wave are derived for linear and circular polarization, it is shown that for linear polarization the co-polar diffraction image consists of an elliptically shaped bright region followed by dark and bright zones. On the other hand, the cross-polar image consists essentially of four bright spots separated by a dark cross. These theoretical findings were confirmed by measurements. With circular polarization the co-polar diffraction image comprises a bright central circle followed by dark and bright rings, whereas the cross-polar image consists of a dark central circle followed by bright and dark rings. It is also shown that the field distribution in the image space is affected to a great extent by the angular semiaperture ψ. Graphs of the variation of the image characteristics with ψ are also given.
- Publication:
-
IEEE Transactions on Antennas and Propagation
- Pub Date:
- July 1976
- DOI:
- 10.1109/TAP.1976.1141377
- Bibcode:
- 1976ITAP...24..418G
- Keywords:
-
- Circular Polarization;
- Focal Plane Devices;
- Parabolic Antennas;
- Plane Waves;
- Polarization Characteristics;
- Wave Diffraction;
- Coplanarity;
- Crossed Fields;
- Diffraction Patterns;
- Electromagnetic Fields;
- Focusing;
- Radiation Distribution;
- Communications and Radar