The occurrence of passive intermodulation and troubleshooting in Thailand mobile industry

Abstract

This paper describes the problem of the passive intermodulation (PIM) in mobile communications. We focus on the problem occured between the transmitter and antennas. The paper starts from the theory of intermodulation, mathematics concept and effect in mobile channels. The problem occured when two or more signals frequencies are transmitted at the same time in the same passive device. The non-linear behavior produced spurious signals where the frequencies were linear combinations of the frequencies of the original signals. When PIM level occurred,we measured such level and find out the methods to reduce PIM level. Finally,we got some methods in reducing PIM level to meet IEC 62037 standard.