Transmit/receive front-end electronics for 3D acoustic imaging

Medical ultrasonic imaging systems, in general, are composed of a transducer element and the transmit/receive electronics. One dimensional arrays produce a two-dimensional cross-sectional image of the medium. With recent advances in transducer technology, the fabrication of 2D arrays became feasible; they can be used for 3D (volumetric) imaging (Oralkan, Ö. et al., IEEE Trans. Ultrasonics, Ferroelectrics and Frequency Control, vol.49, no.11, p.1596-610, 2002; Proc. IEEE Ultrasonics Symp., p.1083-86, 2002). However, the Nyquist criterion restricts transducer dimensions, which results in relatively less sensitive array elements. Consequently, for an image of acceptable quality, the receiver electronics must be improved. The design of CMOS based transmit/receive front-end electronics for 2D transducer arrays is described. The circuit is composed of a high voltage pulser, a transmit/receive switch, a low noise amplifier, and a bonding pad for connection to the transducer element.