Double element ultrasonic transducer modelling with VHDL-AMS for lossy piezoceramic.
Résumé
This paper presents a double element piezoceramic transducer modelling coupled with its electronics with VHDL-AMS referenced IEEE 1076.1. Piezoceramic double element is used for its sensibility at two different frequencies and dedicated to harmonic generation measurement in non linear ultrasonic domain. It was composed by a first element with a piezoceramic ring structure vibrating at a frequency of 2,25 MHz in thickness mode. The second element is stuck into the center of the first. This geometrical form is a disc vibrating at 4,5 MHz in thickness mode too. Transducer modelling with electronic and acoustic environment are studied with electrical and mechanical losses of the piezoceramic material. Transducer is implemented into VHDL-AMS with the Redwood model based on the piezoelectricity equations. To estimate transducer performance, we simulate pulse voltage response for each element. Results obtained for a P188 piezoceramic transducer show that transducer losses must be take into account in performance evaluation.