Linearly constrained minimum variance beamforming with quadratic pattern constraints for spatially spread sources

Antenna arrays that receive emissions from spatially spread sources require beamformers with wider beamwidths than point source beamformers. The framework of linearly constrained minimum variance beamforming with quadratic pattern constraints (LCMV-QPC) is used to develop beamformers with a specified main beamwidth and sidelobe levels. The problem is formulated by imposing a set of inequality constraints on the mean-square error between the achievable beampattern and an ideal beampattern over a set of angular regions. The technique is used to synthesize quiescent beamformers with the desired beampattern characteristics for circular and cylindrical arrays.