Improved eigenfilter-based time-domain wideband beamforming

An improved eigenfilter-based wideband beamforming method with frequency invariance and nulls was proposed. Based on the optimization model formed by maximum energy array cost function and linear constraints of array response in main great direction, array spatial response variation was integrated into the cost function to achieve frequency invariance. Two methods, integrating the extended sidelobe energy into cost function and using linear constraints of array response in the direction of inference, were designed to achieve nulls, so that two new constraint optimization models were formed, which could be solved by eigenfilter. Simulation results show that frequency invariance and nulls of beam response are achieved at the specified angle region in the frequency passband, and the gain of the sidelobe is small, the effectiveness and satisfactory performance of the proposed method are proved.