The invention discloses a vehicle-mounted Ku
wave band satellite communication small-bore antenna
system which comprises an antenna reflecting surface, a feed source, an LNB (
low noise block downconverter), a receiving-transmitting
duplexer, an antenna controller, and the like. A one-to-two shunt is arranged on a bottom plate of an antenna rotating platform, and output signals of the LNB are divided into two paths through the one-to-two shunt, wherein one path of signals are transmitted to a
satellite beacon receiver for tracking the antenna, while the other path of signals are transmitted to a modulator-demodulator through a
waveguide / coaxial rotary joint. After the antenna is started, the antenna automatically searches the
satellite, i.e. carries out open loop tracking, and once the antenna finds the satellite, the antenna carries out close loop tracking. The invention has compact and simple structure, light weight of the whole antenna
system and fast response. An adopted three-dimensional coordinate
system is a dynamic coordinate system moving along with the antenna, and a piezoelectric type
angular rate sensor is respectively arranged on the three coordinate axes so as to ensure that the antenna is exactly aligned to the satellite.