Adaptive and non-adaptive beampattern control using quadratic beampattern constraints

A general framework for adaptive and non-adaptive beampattern synthesis based on minimum mean-square error (MMSE) beamforming with quadratic beampattern constraints is presented. Main beam and sidelobe pattern control is achieved by imposing a set of inequality constraints on the weighted mean-square error between the adaptive pattern and a desired beampattern over a given angular region. By proper choice of angular regions and desired beampatterns in each region, we can trade off the level of pattern control with algorithmic complexity. The technique is used to synthesize a nearly uniform sidelobe level quiescent pattern for a non-linear array, and to control sidelobe levels for the same array in an adaptive manner.