Design of frequency invariant beamformer without temporal filtering

A novel method for the design of frequency invariant beamformers for uniformly spaced three-dimensional (3-D) arrays is proposed. Unlike the traditional method, which is based on the use of temporal filtering, the proposed design can achieve a frequency invariant response without employing any temporal filtering process and the resultant beamformer does not suffer from the beam broadening effect at high off-boresight steering angles. A design example is provided to show the effectiveness of the proposed method.