XM Satellite Radio Technology Fundamentals

In October of 1997, the Federal Communications Commission (FCC) granted two national satellite radio licenses. The FCC allocated 25 MHz of the electromagnetic spectrum (2.3 GHz frequency band) for satellite digital broadcasting to two companies: 12.5 MHz to XM Satellite Radio and 12.5 MHz to Sirius Satellite Radio. This paper is an overview of the XM Satellite Radio technology. Four major components of the overall Network are described: a) The ground segment; b) The space segment; c) The terrestrial repeater segment and the d) The technology segment. Mobile antenna design challenges are also being addressed and optimum antenna configurations are presented.