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.