Numerical analysis of passive intermodulation due to metallic contact nonlinearity

A new numerical method for the study of passive intermodulation is presented against the limitations of time-domain physical optics(TD-PO). The equivalent circuit model of the metal junction that introduced into the full-wave method is established. The passive intermodulation products and the electromagnetic field excited by passive intermodulation products as secondary sources can be analyzed by full-wave method with nonlinear circuit model. Compared with the time-domain physical optics, the proposed method can eliminate the accumulated error from time iteration on objects large in term of wavelength, and can be applied on complicated microwave structures. The numerical results demonstrate the effectiveness of the method in this paper which provides a new method for the analysis of nonlinear problem.