Test technique for passive inter-modulation distortion

In the high-power multi-channel communication system, once passive inter-modulation (PIM for short) signal falls within receiving frequency band, they will greatly influence on signal receiving in communication system. At first, an overview of the cause of PIM distortion in communication systems is given in the paper, and the measurement method of PIM distortion is introduced. A PIM test system is also presented in this paper, which is controlled by a computer. It uses the software system independently developed by ourselves, and can be applied in several measurement bands of PIM. The PIM test system can improve its measurement accuracy by calibration. Comparing with the measurement data for standard parts, this test system has higher measurement accuracy. The tests of different operators for different devices are carried out in several times, the test results show that this test system has very good reliability and repeatability.