Localization Of Passive Intermodulation Based On The Matrix Pencil Method

The theme of this paper is the localization of Passive intermodulation sources.Passive intermodulation(PIM)is a form of nonlinear distortion which is caused by the electromagnetic nonlinearity of passive devices in high power wireless communication systems.The detection of PIM sources is crucial to suppress the PIM products effectively.In this paper,we indicate that based on an extended reflection type PIM measurement system,if three coherent sources and an amplitude and phase measurement circuit can be introduced into the PIM testing system,a PIM localization system can be designed.In order to measure the amplitude and phase of the PIM signal,three coherent sources are used as two-tone signal and reference PIM source,respectively.Algorithms for single PIM source localization and MPM-based(matrix pencil method)multiple PIM sources localization are proposed based on the k space PIM signals.The single PIM localization algorithm can realize the fast localization for the PIM source and is free of measurement bandwidth.And the MPM-based localization of PIM is robu'st to locate PIM sources accurately without any prior knowledge.Experiments of PIM localization have been implemented on coaxial lines,filters,diodes,etc.,verifying the effectiveness of the proposed approaches.The results turn out that the proposed algorithms are competent in PIM localization and the error of localization is less than half wavelength.