A mobile 12 GHz DBS television receiving system

A practical, mobile, 12-GHz direct broadcast satellite (DBS) television receiving system for receivers on vehicles is described. The system is housed in a cylindrical radome of 350 mm height and 862 mm diameter, and it weighs 50 kg. Two pairs of high performance flat-panel antenna units (640*180 mm each) are used to reduce the system. For rapid recatch of DBS, antenna control is based on a gyroscope that is corrected using a phase-comparison monopulse. To simplify the system, the antenna units and receivers are used for antenna tracking as well as signal reception. The antenna units are in-phase combined to allow electronic tracking, which reduces the influence of pointing error caused by vibration of vehicles. The system maintains a reception rate of more than 90% on expressways.<
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