Array Mobile Satellite Antennas

This paper outlines the state-of-art of Array Mobile Satellite Antennas (MSA) and describes their designs, benefits and specific impacts in Mobile Satellite Communications (MSC). In many respects the MSA infrastructures currently available for MSC constitute the weakest links of the system. If the mobile antenna has a high gain, it has to track the satellite, following both mobiles and satellite orbital motions. Namely, sometimes this is difficult and expensive to synchronize. Therefore, if the vehicular antenna has low gain, it does not need to perform tracking but the capacity of the communications link is limited. The MSA can send signals via transmitter (Tx) and receive via receiver (Rx) in the same time, or can be Tx or Rx only. On the other hand, all MSA are classified into omnidirectional and directional tracking antennas. All MSC GEO and Non-GEO current and forthcoming operators have conducted research on all network segments, including different types of MSA and their future development and improvements. The type of MSA in general and the array antennas for MSA applications are discussed.