Adaptive digital beamforming radar for monopulse angle estimation in jamming

This paper describes a digital beamforming architecture for nulling a mainlobe jammer and multiple sidelobe jammers while maintaining the monopulse angle estimation accuracy. It involves two-stage processing using adaptive digital beamforming followed by a mainlobe jammer canceller. A mainlobe jammer blocking matrix and constrained adaptation are employed during the adaptive sidelobe cancellation so that the results of sidelobe jammer cancellation process do not distort the subsequent mainlobe cancellation process. This technique is developed to determine the angular location of a target by maintaining the estimation accuracy of the monopulse ratio in the presence of jamming.