Simulation Method of Passive Intermodulation caused by a Short Source in Standing Wave

摘要

This study explained a simulation method of PIM variation caused by a shorter source than half wavelength using an equivalent resistance expressed as lumped constant in a standing-wave coaxial tube method. The current distribution on the specimen was approximated as a sine wave. Then the power consumption by the distributed PIM source was calculated. Because it showed the same power consumption from the loading lumped resistance, we .estimated the equivalent lumped resistance used by an electromagnetic (EM) simulation. Comparison revealed that EM simulation with the lumped resistance enabled calculation of the scattering parameter of the distributed PIM source. The PIM tendency to the PIM source length was calculated using the obtained scattering parameter. Then we compared the PIM characteristics of the experiment with those of the calculation. The results demonstrated that we can control the PIM level in a range of 18dB and estimate the variation of PIM using only simulation results.