A Novel Nonlinear Model for Passive Intermodulation in Coaxial Connectors

A novel nonlinear model describing the passive intermodulation (PIM) behavior in coaxial connectors is developed based on sine function. Two types of coaxial connectors are selected as test samples, and a series of two-tone PIM tests are conducted. The coefficients of the sine function model for these connectors are obtained by fitting the test results using ordinary least squares (OLS) method. The predicted results of the sine function model agree well with the test results, which prove that the sine function model can be used to describe the third-order and the fifth-order PIM performance of coaxial connectors accurately. The differences between the sine function model and other nonlinear models are compared.