SCHWARZSCHILD RADAR ANTENNA OPERABLE IN SECTOR SCAN AND CONICAL SCAN MODES WITH ANTI-BLOCKAGE REFLECTOR

摘要

A Schwarzschild radar antenna has an organ-pipe scanner for producing relatively wide angle unidirectional sector scans of a high-gain pencil beam. When conical scanning is desired, energy from selected pipes of the organ-pipe scanner is directed to a nutating mirror that reflects the resulting conical scan to the reflectors of the antenna that reflect conical scan energy to the far field. A rotatable disc behind the main reflector controls the size of the aperture therein and provides decreased blockage when the antenna operates in the conical scanning mode.