SAW devices on frequency harmonics. Features of calculation of SAW parameters by the finite element method

Background and Objectives: Acoustoelectronic devices (filters, delay lines, resonators, etc.) are used in a wide range of applications in various industries. Surface acoustic waves (SAW) filters are key elements of wireless communication systems, such as base stations, satellite communication and mobile systems. The aim of this work was to investigate the issue of designing SAW devices on frequency harmonics, which potentially allows you to work at higher frequencies. To design devices using a model of coupling of modes (COM), a set of SAW parameters is required. Materials and Methods: A technique for extracting SAW parameters of the main and multiple frequency harmonics under the electrodes using the finite element method in COMSOL are presented. The methodology and the main features of the analysis of SAW by the numerical method are considered. Then, based on the extracted parameters, a quartz SAW filter and a lithium niobate SAW delay line were calculated using transducers operating at the 3rd harmonic. The results of calculating the frequency response were compared with the results of the experiment. Results and Conclusions: The proposed algorithm allows to extract the SAW parameters of each of the harmonics and take them into account in quick calculations on base COM. The results of numerical analysis of the SAW parameters, a COM model and a matrix approach to formalizing calculations provide the developer with an effective and easily adaptable tool for calculating the frequency responses of SAW devices.