Multifunction personal and mobile SMM antenna for satellite communications systems

There are a number of personal and mobile communications systems based on the use of microwave links relayed by Earth-orbiting satellites between small, low-cost Earth terminals using antennas of low directivity and broad beam aiming at the appropriate satellites. These satellite communications systems are now either deployed or in various stages of development and planning. For example, there are the AMSC geostationary satellites covering North America. There are the fully operational GPS systems of the US and GLONASS of Russia that both allow the determination of positioning on Earth with high accuracy. The bold and ambitious vision of linking people and businesses in the most remote corners of the globe by satellites, specifically the low-Earth-orbiting (LEO) satellites, which was considered by many as a dream, is now becoming reality. The ongoing Iridium project, a consortium led by Motorola, plans to have 66 LEO satellites carrying messaging, data, and voice services starting in 1998. This paper presents a preliminary design for the needed personal and mobile Earth-terminal antennas.