Passive Intermodulation Models of Current Distortion in Electrical Contact Points

This letter presents a novel method for modeling passive intermodulation induced by current distortion in electrical contacts. A piecewise function for the current is proposed as the nonlinear transfer function to the contact points. The lower and upper cutoff amplitudes are determined by the input powers and the number of contact points. The third-order intermodulation power is mathematically modeled by using the first-order Chebyshev polynomial. Four coaxial connectors of different types are theoretically modeled and experimentally measured in the Global System for Mobile communications 900-MHz frequency band. A good agreement is obtained between the predictions and measurements with a 0.6-dB mean error in high-power transmission.