Passive Intermodulation of Metallic Contact in Radiation Field

Abstract

In order to evaluate the passive intermodulation (PIM) level induced by metallic contact structure located in the radiation field near the receiving antenna, a calculation method for predicting the amplitude of PIM received by the antenna is proposed and demonstrated in the paper. Adopting the PIM point source model, and based on the simulating of carrier excitation current amplitude and intermodulation signal coupling efficiency to calculate PIM level of metal contact in radiation field. By employing the slotted waveguide tooling based on near-field coupling test principle, we measured the third-order passive intermodulation (PIM3) level of the two copper wire contact junction located in the near-field radiation field of the slotted waveguide and analyzed its position distribution dependence. The experimental measured results are in good agreement with theoretical calculations, which validates the proposed calculation method of the PIM level induced by metallic contact junction in radiation field. This work provides an analytical method for its evaluating PIM products, and contributes to an in-depth understanding of the mechanism of PIM induced by metal contact in radiation field.