Electronic Journal Technical Acoustics ISSN 1819-2408

Fréderic Coutard, Etienne Tisserand, Patrick Schweitzer

Optimal low noise amplifier for ultrasonic receptor

language: English

received 12.06.2007, published 01.08.2007

Download article (PDF, 250 kb, ZIP), use browser command "Save Target As..."
To read this document you need Adobe Acrobat © Reader software, which is simple to use and available at no cost. Use version 4.0 or higher. You can download software from Adobe site (http://www.adobe.com/).

ABSTRACT

The paper describes a detailed investigation of the noise generated by an ultrasonic chain of reception carried out on a piezoelectric receiver of standard characteristics amplified by an LNA (Low Noise Amplifier) of optimum design. The objective is to provide the conditions which will allow the best signal-to-noise ratio of the entire chain. The noise chain factor is studied theoretically. It is shown that the noise factor is minimal if the noise characteristics of the LNA and the gain resistance of the first amplification stage are jointly matched to the transducer’s internal resistance. A two-stage 56 dB amplifier optimized for transducers with a resonant frequency between 1 and 10 MHz and with an internal resistance of approximately 390 ohm is designed. Experimental measurements show a low noise factor (1.46). This advantage reveals the direct correlation between noise PSD of the chain and the real part of the transducer impedance.

Keywords: ultrasonics, piezoelectric transducer, low noise amplifier, optimum design

7 pages, 6 figures

Сitation: Fréderic Coutard, Etienne Tisserand, Patrick Schweitzer. Optimal low noise amplifier for ultrasonic receptor. Electronic Journal “Technical Acoustics”, http://www.ejta.org, 2007, 15.

REFERENCES

1. IEEE Standard on Piezoelectricity, N°176, 1987.
2. J. Karki. Calculating noise figure in op amp. Texas Instruements Incorporated, Analog Applications Journal, 4Q, 2003.
3. Coutard Frédéric, Schweitzer Patrick, Tisserand Etienne. Simulation under Cadence of the Redwood model with the electronic chain conditioning, REM-2005, June 30th – July 1, 2005, France.
4. A. Puttmer, P. Hauptmann, R. Lucklum, O. Krause, B. Henning. SPICE Model for Lossy Piezoceramic Transducers. IEEE Trans. Ultrason. Ferroelectr. Freq. Control, vol. 44, N°1, January 1997.
5. Jan van Deventer, Torbjörn Löfqvist and Jerker Delsing. Pspice Simulation of Ultrasonic Systems. IEEE Trans. Ultrason. Ferroelectr. and Freq. Control, vol. 47, N°4, July 2000.
6. Y. Yanez, M. J. Garcia-Hernandes, J. Salazar, A. Turo, J. A. Chavez. Designing amplifiers with very low output noise for high impedance piezoelectric transducers. NDT&E, vol. 38, 2005, 491–496.
7. G. Hayward, R. A. Banks and L. B. Russell. A Model for Low Noise Design Ultrasonic Transducers. Proc. IEEE Ultrason. Symp., 1995, 971–974.
8. Vincent Beroulle, Yves Bertrand, Laurent Latorre, Pascal Nouet. Monolithic piezoresistive CMOS magnetic field sensors. Sensors and Actuators, A 103, 2003, 23–32.
9. J. W. Young. Optimization of acoustic receiver noise performance. J. Acoust. Soc. Am., vol. 61, N°6, June 1977, 1471–1476.

		Frédéric COUTARD was born on 1978 in France. Since 2003, he works at the electronics laboratory of Nancy. He received his Ph. D. in 2007 in Instrumentation and Microelectronics. His research interest is modelling and optimizing the design electronics for the integrated ultrasonic systems.
		Etienne TISSERAND was born on 1962. He received his Ph. D. in 1987 in Electronic and Measurement technology. Actually, He is an Associate Professor in the Henri Poincaré University of Nancy, France. Areas of research interest are the piezoelectric sensors, instrumentation and signal processing.
		Patrick SCHWEITZER was born on 1964. He received his Ph. D. in 1994 in Electronic and Measurement technology. Actually, He is Associate Professor in the Henri Poincaré University of Nancy, France. Areas of research interest are the piezoelectric sensors, instrumentation and signal processing. e-mail: Patrick.Schweitzer(at)lien.uhp-nancy.fr