Spatial filtering with broadband mimimum variance beamformers

This paper describes procedures for controlling the response of linearly-constrained minimum variance broadband array/beamformer structures. The procedure enables specification of gain and spatial derivative characteristics, over selected bands of frequency, for multiple points and does not require the use of steering delays. An efficient orthogonal representation for impinging broadband sources is developed and used to specify a minimal set of constraint equations for the beamformer. These equations assure that the resulting structure has the desired response at the specified locations.