Abstract: An embodiment of a system for determining a distance and magnitude to one or more unknown passive intermodulation (PIM) sources associated with a network under test comprises a scalar PIM measuring instrument and a reference PIM source. The scalar PIM measuring instrument has an output frequency that is systematically changeable to produce a series of response signals of varying frequency and the reference PIM source is configured to introduce a reflected signal to the scalar PIM measuring instrument in response to the output frequency. The scalar PIM measuring instrument can perform data processing algorithms allowing the extraction of distance and magnitude information about the unknown PIM sources located along the network under test from scalar data received by the scalar PIM measuring instrument. The scalar data received by the scalar PIM measuring instrument represents a combination of signals from the unknown PIM sources and the reference PIM source.

Abstract: A handheld vector network analyzer (VNA) providing a wide bandwidth test signal F.sub.O utilizing a narrowband test signal synthesizer which provides the test signal through a frequency divider or harmonic generator. With a 550-1100 MHz narrowband test signal synthesizer, a test signal F.sub.O can range from 25 MHz to 3.3 GHz. To make a tracking synthesizer operate more independent of the test signal synthesizer, a LO signal is produced using the tracking synthesizer with its phase detector input connected through a frequency divider to the output of the test signal synthesizer. Synchronous detectors are further included which provide incident and reflected IF signals to take advantage of the maximum range of an A/D converter. To better enable operation in the presence of external signals, feedback is provided from the synchronous detectors to sweep the frequency of a reference oscillator.