Motion Induced Antenna Pointing Errors in Satellite Communications On-The-Move Systems

Satellite communications on-the-move systems that operate at the Ku-band (11-14 GHz band) and higher frequencies play a significant role in military and civilian communication systems. In order to limit interference to adjacent satellites, regulatory and standards bodies have established strict limits on the effective isotropic radiated power (EIRP) at a particular terminal in its off-axis direction. In communications on-the-move systems, because of the frequent motion of the antenna platform, antenna pointing errors are unavoidable. In this paper we demonstrate that such antenna errors will result in the EIRP exceeding the limit imposed by the standards and regulatory bodies. Also, in order to support mobile antenna terminals, a modification to the existing EIRP spectral density is suggested.