Via Impact on Passive Intermodulation Distortion in Planar Circuits

This work presents the passive intermodulation (PIM) induced by vias in microwave circuits. An analytical model combining the equivalent nonlinear source theory and the vector superposition principle is established to evaluate the PIM product of the vias array, which is influenced by the combination effect of the vias location, diameter, and number. The proposed model is verified and evaluated at 2.6 GHz. Good agreement between theory and experiment proves the logic and practicability of modeling. This work provides guidance for the low PIM optimization design of vias.