Resolution enhancement of digital beamformers

Large array extent is usually required in order to adequately enhance the resolution of a beamformer and to improve its beam pattern. Due to physical constraints this requirement may not be met. This paper presents the results of an analytical and experimental study in the use of a signal extrapolation method to enhance the beamformer resolution for small array extent. A real-time implementation scheme is proposed. It is shown that the beam pattern and the resolution of the beamformer can be improved. Examples for various situations are provided.