Although not a new problem and well known to the satellite communications and microwave trunking industries, until the use of cellular phones became widespread, Passive Intermodulation Distortion (PIM) was of little concern to the connector designer. Until five years ago, most connector engineers had never heard of the phenomenon. Now, due to the frequency plans of today’s modern base stations, the use of higher transmitter power levels and more sensitive receivers, PIM has surfaced as a potential problem for GSM, DCS, PCS and other wireless services.
In order to effectively design low PIM connectors and cable assemblies, an in-depth understanding of PIM is needed. This paper will discuss the causes, impact, and measurement of PIM. Guidelines to designing low PIM connectors and cable assemblies will be outlined including a discussion of the latest test procedures being developed by the international community. A look towards future requirements will also be discussed.
