Scanning capabilities of large parabolic cylinder reflector antennas with phased-array feeds
Abstract
Two methods of scanning large parabolic cylinder antennas are examined: one method moves a small array across the focal plane to form a scanning beam; the other method employs a larger stationary array which is capable of electronically scanning the beam. With conventional single-element feeds, the maximum possible scan angle decreases with increasing reflector size. With array feeds, however, the scan limits are shown to be independent of reflector size and antenna gain. Antennas with movable array feeds are found to have high performance (high gain and low sidelobes) even when scanned more than ten degrees off axis; antennas with stationary array feeds degrade rapidly beyond about one degree of scan because of aperture blockage. Off-axis designs which eliminate the aperture blockage are shown to extend the coverage of antennas with stationary feeds to about plus or minus 5 degrees.
- Publication:
-
IEEE Transactions on Antennas and Propagation
- Pub Date:
- May 1981
- DOI:
- 10.1109/TAP.1981.1142617
- Bibcode:
- 1981ITAP...29..455M
- Keywords:
-
- Antenna Design;
- Antenna Feeds;
- Antenna Radiation Patterns;
- Parabolic Reflectors;
- Phased Arrays;
- Reflector Antennas;
- Steerable Antennas;
- Electronic Control;
- Focal Plane Devices;
- Microwave Antennas;
- Parabolic Antennas;
- Performance Prediction;
- Power Gain;
- Scanning;
- Sidelobes;
- Communications and Radar