Ultrasonic Piezoceramic Transducer Modeling With VHDL-AMS: Application to Ultrasound Nonlinear Parameter Simulations

This paper presents an ultrasonic transducer modeling with very high-speed integrated circuit (VHSIC) hardware description language-analog and mixed signal (VHDL-AMS) IEEE 1076.1 integrated in a global measurement cell modeling dedicated to biological tissue ultrasound characterization. Usual modeling of ultrasonic transducers is based on electrical analogy and is not simulated in the global measurement environment. The ultrasonic transducer modeling proposed is simulated with a nonlinear acoustic load and electronic excitation. The nonlinear B/A parameter is used to characterize a medium with a comparative method. The measurement cell is composed of two piezoelectric ceramic transducers, which are implemented with Redwood´s electric scheme. The analyzed medium is placed between the transducers and modeled to take into account the nonlinear propagation with the B/A parameter. The usual transmission line model has been modified to take into account the nonlinear propagation for a one-dimensional (1-D) wave. Simulations of the transducer pulse response and electrical impedance show a VHDL-AMS model that is in good agreement with measurement and compared to the usual personal computer simulation program with integrated circuit emphasis results simulations. Results obtained by simulation of mediums (blood, milk, liver, and human fat tissue) showed good agreement between modeling and experimental measurement, and a maximum error of about 12.5% for B/A measurement-simulation