A New Beamforming Process Based on the Phase Dispersion Analysis

To improve the results of the Delay-And-Sum (DAS) beamformer a weighting factor based on a measurement of the phase dispersion of the signals in the image point under consideration has been proposed. With this objective, the spectral analysis of the phase dispersion is used here to obtain a new descriptor that can be easily computed and introduced as a ponderation factor in the beamforming process. Theoretical results show that, for a linear array of 32 elements operating in synthetic aperture technique with dynamic focussing in emission and reception (Total Focussing Method) the improvement can reach up to 24dB. In order to validate the theoretical hypothesis, experimental results obtained using a linear array of 64 elements (2,4MHz) and a CIRS 040GSE phantom also are presented.