The electrodes for a CMUT are split to provide separate transmit and receive bias and alternating current electrodes. The transmit electrodes of different elements are interconnected, such as rows sharing bias and columns sharing transmit alternating signals. The bias is used to select an aperture in elevation, and only a sufficient number of transmit beamformer channels to use the selected aperture are needed. On receive, the full multi-dimensional array may be used with integrated beamformer electronics.
