A circuit model for nonlinear simulation of radio-frequency filters employing bulk acoustic wave resonators

This paper describes a circuit model for the analysis of nonlinearity in the filters based on radio-frequency (RF) bulk acoustic wave (BAW) resonators. The non-linear output is expressed by a current source connected parallel to the linear resonator. Amplitude of the non-linear current source is programmed proportional to the product of linear currents flowing in the resonator. Thus the non-linear analysis is performed by the common linear analysis even for complex device structures. The analysis is applied to a ladder-type RF BAW filter, and frequency dependence of the non-linear output is discussed. Furthermore, this analysis is verified through comparison with experiments.