Modeling of Linear-Nonlinear Behavior in Electrical Contacts With Interaction Interference

Abstract

The reliability of electrical contacts is important to the quality of signal transmission. In this letter, an equivalent circuit model is proposed to illustrate the linear-nonlinear interaction effect in coaxial connectors. The linear region is simplified to a cascade system composed of impedance matching and impedance mismatch networks, while the nonlinear region is equivalent to a contact impedance network coupling a module defined by nonlinear I-V relation. By tuning values of each component in the presented circuit, the effect of linear and nonlinear elements on scattering characteristics and passive intermodulation (PIM) are observed. The S-parameters are sensitive to linear network with equivalent inductance and capacitance, but the PIM behavior is affected by both nonlinear resistance and linear resistance which are temperature and frequency dependent. Connectors with designed contact resistance are tested separately in different frequency band and environmental temperature, verifying the proposed model in predicting scattering performance and PIM behavior.