Frequency-scanned Planar-array Microwave Antenna, 1956-1960

This is a unique frequency-scanned planar-array microwave antenna with raster scans accomplished by frequency shift only. It was a prodigious effort of engineering and science in the forefront of microwave and radar design.

This type of microwave antenna used in the mid-1950s by the USA, USST and the UK made “jumping cracker” arrays for scanning in one plane but the antenna was rotated in the azimuth. Such antennas were fitted to US Navy and USSR Navy warships. By the 1990s, large US Navy aircraft carriers were fitted with large plane microwave antennas but used electronic scanning.

This helically-fed raster-scan antenna was considered “before its time” and was a remarkable achievement of the microwave and construction techniques in the mid-1950s.