Adaptive sum and difference beampattern of array radar encounters some problems

such as signal cancellation

finite sample supports

beam-pattern maintaining and zero-point constraint and so on.In this paper

an adaptive sum and difference beamforming approach based on magnitude and phase response linear constraint is proposed.In this method

magnitude and phase response constraints on several other directions are set and these directions are around that of the assumed signal.This robust beamforming approach effectively overcomes the signal cancellation problem and shows considerable improvement in signal-to-interference-plus-noise ratio (SINR).Through imposing these constraints on both magnitude and phase responses

the sum and difference beamformers are drawing up to the standard static beamformers at the region of the main beam.This approach is robust against signal presence in training data.And through properly setting the magnitude and phase constraints

we can implement azimuth and elevation uncoupling in monopulse angle estimation.Simulation examples demonstrate the effectiveness of the proposed method.