On the efficacy of in-probe pre-amplifiers for piezoelectric 2D arrays

Transducer arrays for 3D imaging are characterized by elements distributed over a 2D surface. The dimensions of each element are typically one half-wavelength in both x- and y-directions. Such small elements inherently have a high electrical impedance. When the elements are connected to a probe cable, the high cable capacitance decimates the delivered voltage and results in a poor Signal to Noise Ratio (SNR). This may have dramatic effects, especially in sparse arrays, where a small number of elements contributes to the beamformed signal. In this paper we demonstrate that the use of in-probe preamplifiers in a sparse PZT probe is valuable to significantly increase the SNR.