Measurement of ultra low passive intermodulation with ability to separate current/voltage induced nonlinearities

A measurement technique is proposed which exploits the standing wave in a microstrip resonator to more thoroughly measure passive nonlinearities. The measurement technique is demonstrated to be able to measure the difference between current induced and voltage induced passive nonlinearities. By placing the device under test in a resonator three times higher voltage and current magnitudes are created compared to traveling wave passive intermodulation measurement systems. This increases the effective power only at the device under test and increases the measurement sensitivity of the original traveling wave measurement system. Based on our measurements we project the ability to characterize devices at -196 dBc, a 29 dB improvement over the original system.