Patent attributes
A measuring instrument for detecting a source of passive intermodulation (PIM) includes a signal source, a reference signal source, and a first transmitter module and a second transmitter module each configured to receive a signal from the signal source and a reference signal from the reference signal source and generate a tone at a first frequency and a second frequency, respectively. The measuring instrument further includes a receiver and a receiver module configured to receive the signal from the signal source and a harmonic of the test signal generated by a source of PIM to generate a sample signal at the fixed frequency of the reference signal. The receiver is configured to determine a shift in phase between the reference signal and the sample signal. The receiver determines an estimate of distance to the source of PIM using determinations of the shift in phase as the signal source is swept.