Development and test of a multibeam array payload for satellite communication with mobiles

A multibeam array payload for satellite communication with mobiles has been developed, built and tested. The multiple beam system is of a planar phased array type, where beam-forming is performed at IF and where power amplification is performed at RF behind the antenna elements. Special hardware developed include an array of 18 short backfire elements, 18 L-band linear power amplifiers, temperature compensated dielectric resonator diplexers and a 19 x 18 beam-forming network at IF. A multibeam transmit system has been integrated using the hardware as mentioned above together with beamswitching equipment, and interface equipment for testing. Tests have been performed on a fully automatic far field outdoor range, and predicted system performance has been verified. It has been demonstrated that a powerful multibeam array payload is feasible for use in a global communications system with mobiles.