Digitally beamformed multibeam phased array antennas for future communication satellites

Abstract

Future generation of communication satellites are based on multi-beam phased array antennas, where beamforming and scanning are all fully implemented in digital domain as opposed to the commonly considered analog domains. The challenges of realizing a digitally beamformed multi-beam phased array antennas are many when communications are intended for applications beyond Q-band communication satellites, where RF down-conversion, phase control and timing synchronization, analog-to-digital conversion, and ultra high-speed data links are the important functions before the digital signal processing function could be implemented. The down-conversion and phase shifting could be combined using ILPLL systems that are implemented in both electrical and optical domains. Design of a novel all-optical ADC using spectral technique is presented, where sampling speeds as high as 50GS/s with a minimum 6 bits of resolution is attainable with maximum power consumption of 4W. © 2008 IEEE.