Characterisation of passive intermodulation in printed lines

Engineered Passive Nonlinearities for Broadband Passive Intermodulation Distortion Mitigation

“…Passive nonlinearities that generate PIM distortion can occur in wireless system components such as antennas and their matching networks, which are not frequency-filtered by the system duplexing filter. PIM distortion generated in these components is not diminished by a system's filters and can cause severe interference if it falls in the system's receive band [2]. Because the causes and behavior of PIM are incompletely understood, mitigation of PIM distortion is a difficult task.…”

“…Because the gold-plated nickel conductor shown in Fig. 2 is a two-layer system, we utilize the boundary condition relating the first spatial derivatives of the current densities in the two region at their interface (2) This boundary condition can be derived by integrating (1) across an infinitesimal region spanning the boundary. The other three boundary conditions are more familiar, being: the continuity of current density across the boundary between the regions, the fact that the current density decays to zero deep into the nickel region, and that the integration over the solution of (1) yields the total current flowing through the conductor.…”