Abstract
This paper presents a two-dimensional FEM (Finite Element Method) modeling and simulation of a surface acoustic wave (SAW) resonator based on a layered Pt/AlN/Sapphire structure. Such structure that exploits the electromechanical coupling of piezoelectric film is of high interest for harsh environments. By harsh environment we mean any environment that could hinder the operation of the device. Hardness can come from a variety of sources, and examples include the following: High pressure, High temperature, Shock/high vibration, Radiation, Harsh chemicals, etc. As part of this work, we are looking for high temperature sensor applications and only operating drifts due to temperature will be studied. SAW resonator is made from piezoelectric thin film Aluminum Nitride (AlN) layer on Sapphire substrate. Modal analysis is used to determine the eigen mode and the eigenfrequency of the system and the study of the frequency domain is used to determine the response of the model under influence of a harmonic excitation for one or more frequencies. In the FEM modeling, various parameters of the surface waves in the films, such as the surface velocity, the displacement of the piezoelectric thin film, the electrical potential, the electromechanical coefficient (k2), and the quality factor (Q) were studied. A comparative study between modeled and experimental curves showed a good agreement and allowed to validate our simulation method. Finally, a FEM study of the influence of normalized thickness of AlN thin film on resonator performances was carried out and compared with theorical results of literature.
Highlights
surface acoustic wave (SAW) (Surface Acoustic Wave) devices play a very important role in modern telecommunications [1]
SAWs are widely used in the electronics industry, for the production of filters, delay lines and resonators operating at frequencies ranging from a few tens of Megahertz to a few Gigahertz [5,6,7]
To fabricate SAW resonator operating in 2.45 GHz ISM band, the spatial period of the interdigital electroacoustic transducers (IDTs) was fixed to 1.7 μm
Summary
SAW (Surface Acoustic Wave) devices play a very important role in modern telecommunications [1]. We discuss the finite element method [24] modeling and simulation of a one-port Pt/AlN/Sapphire surface acoustic wave resonator. This modeling is carried out in two dimensions using COMSOL Multiphysics [25]. Using modeling we analyze the impact of AlN layer thickness on the performance of resonator To this end, the electrical properties of SAW. The evolutions of the acoustic velocity, the quality factor, and the electromechanical coupling coefficient of SAW devices are presented and discussed as a function of the thickness of AlN thin film
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
