A limited-scan phased-array antenna for use with a clutter-mapping radar system

The design and construction of an electronic-scan phased-array antenna system for use with a clutter-mapping radar system is described. The phased array is capable of
\pm-20\deg
of electronic beam steerng and full hemispheric mechanical steerability. It is composed of 780 short-backfire radiators with a total gain of 36 dB. It is vertically polarized and has phase-monopulse-tracking ability. The electronic beamforming and steering is controlled by a digital system using a PDP-11/20 general-purpose computer system. The same computer is used to control the digital clutter-mapping system, which is composed of an A/D converter, multiplexer, digital tape recorder, high-speed disk storage, and an intensity-modulated graphic recorder.