Narrow beamwidth satellite antenna pointing and tracking

High data rate communication to users having limited performance resources requires narrow beamwidth, high gain antennas to meet link closure requirements. When users are distributed over relatively wide coverage areas, an appropriate design approach may use array antenna technology to obtain adequate link performance. When high gain satellite antennas are used, two challenges must be addressed. The first challenge is to compensate for satellite attitude and stationkeeping variations so that the overall array coverage area remains registered to the intended geographical area. The second challenge is to acquire users that are sparsely distributed over the broad coverage area and for mobile users, track their motion over the communication time with adequate accuracy to avoid excessive antenna pointing loss. In addition, when such systems are used for military applications, these challenges must also be satisfied when interference is present. Techniques to meet such requirements are discussed.