Abstract: Passive intermodulation (PIM) is a common interference of high power multi-channel microwave communication systems. PIM has serious harmful impact on space microwave communication with shared transceiver antenna, high transmitting power and high receiving sensitivity. PIM will widely exist in the space communication for a long time. Effective solving of PIM problems is the prerequisite for successful development and safe operation in-orbit of space communication payload. The PIM problem under ultra-high transmitting and receiving power ratio conditions will be more complicated in China′s next generation of space communication application, and PIM control has become an important key technology in research and development of space engineering. In this paper, the characteristics and research status of PIM problems are summarized from the aspects of mechanism, analysis and prediction, detection and localization, and suppression technology, and the key technology to solve PIM problem is discussed. Furthermore, the focus of PIM research and the development trend of key technologies are deeply analyzed, combining with the background of space application, which provides some references for the PIM research and technology application of space engineering.

Key words: microware communication, passive intermodulation (PIM), nonlinear interference, microwave components, low PIM technology