A comprehensive model of the electrical response of SAW devices submitted to thermal perturbation

Abstract

A comprehensive model for computing the electrical response of surface acoustic wave (SAW) devices is proposed in this paper. Based on a mixed-matrix analysis, it allows for the prediction of any SAW device admittance/impedance at any temperature. In that purpose, the temperature dependences of the wave velocity of course but also of the reflexion coefficient, directivity, conductance and capacitance are established using polynomial developments. The interest of this approach is illustrated for SAW devices on directive crystal cuts for which dramatic changes of the SAW parameters versus temperature may occur, such as the (YXlt)/48.5°/26.7° Langasite (LGS) cut. First assessment elements are shown to illustrate the importance of accurately designing SAW devices operating on extended temperature range.