Mobile satellite vehicle antennas: noise temperature and receiver G/T

Two L-band mobile vehicle antennas designed in support of NASA's MSAT-X program are evaluated in terms of antenna temperature and receiver G/T. The antenna temperature measurement setup is detailed and its accuracy given. The noise test method is capable of +or-20 K accuracy for antenna temperatures of under 300 K. Antenna temperature is measured in locations representative of the mobile satellite environment. Antenna performance is used in conjunction with receiver noise figure to calculate the mobile receiver G/T at each site and thereby obtain a realistic range for this system figure of merit. The significance of mobile G/T for antenna comparison, antenna design optimization, and mobile satellite system operation is discussed. >