The Impact of Contact Pressure on Passive Intermodulation in Coaxial Connectors

A novel behavior model expressing the effect of contact pressure on the passive intermodulation (PIM) performance was proposed and experimentally verified. The finite-element analysis (FEA) model of the central conductor of a typical coaxial connector was developed based on the structural analysis and contact surface modeling. Simulation results identified the current densities in the contact areas. The third-order intermodulation (IM3) power was mathematically predicted by using the nonlinear current truncation distortion model in electrical contact points. Accelerated tests were designed and conducted to produce connector samples with different contact pressures. These samples were measured by a PIM analyzer in a 900-MHz frequency band. Good agreement was obtained between the predictions and the measurements, validating the PIM analysis method and results.