Proposal for an Earth Station Antenna for Geostationary Satellites with a Simple Concept of Beam Steering

摘要

A center feed Cassegrain system with a conical corrugated horn and doubly curved reflector is proposed. The beam shaping has the purposes: reduction of interference with neighboring satellites and beam steering in one direction, e.g. azimuth direction. The beam steering is realized by lateral displacement of the subreflector. The effects of feed displacement are investigated by analytical methods. The radiation characteristics, such as gain and side lobes, are described in detail. A design example of a ground station antenna is given. The radiation patterns at 11 GHz for focused and defocused antenna systems are calculated. Results show 50.5 dBi, half power beam width 0.30 deg and 0.92 deg; in this angle range the cross polarization is greater than 40 dB.