Numerical Model of Piezoelectric Lateral Electric Field Excited Resonator

• Main Authors: Andrey TEPLYKH, Boris ZAITSEV, Iren KUZNETSOVA
• Format: Article
• Language: English
• Published: IFSA Publishing, S.L. 2015-01-01
• Series: Sensors & Transducers
• Subjects: Acoustic resonator; Lateral exciting field; Finite element analysis; Lithium niobate.
• Online Access: http://www.sensorsportal.com/HTML/DIGEST/january_2015/Vol_184/P_2586.pdf

Nowadays, piezoelectric lateral electric field excited resonators are frequently used for development of various acoustic sensors. But, the adequate theory of such resonators is absent. In this paper, the numerical method of calculation of characteristics of the acoustic oscillations in the piezoelectric lateral electric field excited resonators is developed. The developed method is based on the finite element analysis and allows computing the distribution of the components of the mechanical displacement in the piezoelectric plate and electric potential in the piezoelectric plate and surrounding vacuum at arbitrary frequency of the exciting field. This method allows setting various boundary conditions on various parts of a plate surface, including a condition of mechanical damping of oscillations. This allows calculating the frequency dependence of the real and imaginary parts of the electrical impedance/admittance of the resonator. We analyzed a piezoelectric lateral electric field excited resonator, which is based on a 0.5 mm-thick X-cut lithium niobate plate. Two infinitesimally thin metallic electrodes with width of 5 mm were deposited on top side of the plate. The electrodes were deposited in such a way that the lateral field was oriented along the crystallographic Y-axis. Calculations of electric impedance were carried out for various values of a gap in range 1 - 3 mm between electrodes. These results are in quantitative agreement with experimental data. A brief description of experimental set up is also presented.