Low-complexity Low-sensitivity Second-order Broadband 3D Beam Notch Filter

Abstract

A novel digital null-beamforming method has been introduced for the selective attenuation of interfering broadband plane waves based on their spatial direction of arrival in 3D spatio-temporal applications. For this purpose, a transfer function and a signal flow graph for a highly selective second-order broadband 3D Beam Notch filter have been proposed. It has been shown that the broadband 3D Beam Notch filter is capable of recovering 3D plane wave signals of interest in the presence of interfering broadband 3D plane waves of signal-to-interference ratios of approximately -20dB. Among the envisaged applications of the 3D Beam Notch filter is the attenuation of broadband radio-frequency interference plane waves in radio astronomy, selectively, based on the spatial direction of arrival while recovering the signals of interest.