Study on Passive Intermodulation in I.H.P. SAW Utilizing a Nonlinear FEM Model

Accurate nonlinearity-simulation methods are needed eagerly to predict and further help suppress I.H.P. SAW nonlinearity. We first propose and establish a nonlinear FEM model in which the aperture direction was not ignored to accurately calculate the passive intermodulation (PIM) response. The results show the phase characteristics of PIM3 and the impact of the frequency difference between the two input signals on PIM3. The influence of transverse modes on PIM3 is found. Nonlinear elastic effect plays a dominant role in PIM3, so the mechanical effect should be fully utilized to achieve maximum suppression of PIM3.