Electromagnetic modeling of thin-film bulk acoustic resonators

This paper introduces a novel technique for the electromagnetic analysis of thin-film bulk acoustic-wave resonators. The piezoelectric/acoustic linear equations are coupled to and solved together with Maxwell´s equations. For the acoustic propagation, locally monodimensional behavior is assumed, while full-wave three-dimensional Maxwell´s equations are rigorously solved for the complete circuit. The proposed approach is validated for single resonators by comparison with experimental data, providing very good agreement with reduced computational resources. Hence, a complete Agilent Technologies´ nine-resonator passband filter is simulated in order to demonstrate a typical application to a real-world complex problem.