Consideration and implementation of inherent losses in SAW devices

In the past decades, numerical simulation tools have been improved to allow more efficient designs of surface acoustic wave (SAW) devices. Indeed, many phenomena are now taken into account to most closely evaluate the behaviour of the system in real environment. In keeping with these previous works, this paper is devoted to the raising of three current approximations that lead to imprecisions in the computations. As a consequence, this study uses a physical model (Kelvin-Voigt internal damping) to take into account the internal behaviour of the material under stress or strain. Furthermore, losses related to the polarization of the material and to the residual conductivity in the piezoelectric are no more considered as null. After a software implementation of these phenomena, numerical simulations are conducted and calculation/test correlations are carried out.