Low and Medium-Gain antennas for Mobile Satellite Communications (MSC) and Navigation

In this paper are introduced Low-Gain Omnidirectional Antennas for Mobile Satellite Communications (MSC) and Navigation. In many respects the Mobile Satellite Antenna (MSA) infrastructures currently available for MSC and Navigation. Medium and high gain MSA need to track the satellite, following both movements of mobiles and satellite orbital motions. Sometimes this is difficult and expensive to synchronize and have to be introduced in the understanding manner. On the other hand, the vehicular antenna with a low gain does not need to perform tracking but the capacity of the communications link is limited. In such a way, all MSA are classified into omnidirectional or not directional and directional or antennas with tracking system. The Inmarsat, Eutelsat, Cospas-Sarsat, Iridium, Globalstar, Orbcomm, and other Geostationary Earth Orbit (GEO) and Non-GEO current and forthcoming mobile satellite operators have conducted research on all network segments, including different types of MSA and their future development and improvements. The special types of MSA related to the kind of transportation system, such as maritime, land, aeronautical and transportable or portable mobile antenna types are classified. The common types of Low-Gain Omnidirectional Antennas and Medium-Gain Directional Antennas are introduced in the technical ways as of importance for MSC.