Waveform generation and signal processing for a multifunction radar system

A multifunction, single platform RF sensor capable of performing target acquisition and tracking, combat identification, high data rate communications, and active protection is of interest to the USA army. The sensor ultimately must tie affordable and the size minimized to meet the demands of a rapidly deployable force. To address these needs, the Army Research Laboratory has built and tested a multifunction radar test bed capable of performing multiple tasks simultaneously at K_a-band. The system has integrated high-end RF components together with commercial-off-the-shelf (COTS) signal processing technology. Key elements of the test bed are a commercial direct digital synthesizer (DDS) for adaptable waveform generation, multiple COTS field programmable gate array (FPGA) processors for real-time data acquisition and signal processing, a COTS FPGA based multi-port input/output (I/O) board programmed for radar timing and control, and an electronically scanned antenna (ESA) based upon a Rotman lens beam-former with active elements for multi-beam generation. The radar is capable of transmitting and receiving two simultaneous and independent beams in azimuth with up to 3 GHz of bandwidth and up to 8 watts of average power. The current configuration uses one beam for a radar target acquisition function and the other for a high data rate communication channel. The emphasis of this paper is on the radar´s waveform generation and signal processing capability.