A novel feed network for a sectoral conical beam forming array antenna

Satellite communication can support services in areas where it is hard to construct base stations. However no obstacle should be in the line of sight and a high gain antenna which points to the satellite is necessary. Vehicles like cars and trains move, so a beam forming array antenna is required to construct high gain beams to the satellite. An adequate feed network is necessary to generate adaptive beams in a changing environment. Controlling adaptive beams requires phase shifters in the feed line of the array antennas or switches to select a beam which has already been constructed by the feed network. Phase shifters increase the price and complexity of the antenna system, so switched beam-forming networks have been investigated. This paper proposes a novel feed network for a 2 x 2 array antenna to construct a sectoral conical beam to communicate with satellites in geostationary orbits for Satellite Digital Multimedia Broadcasting (S-DMB) in Korea.