Passive intermodulation considerations in antenna design

Abstract

The author outlines the causes of PIM (passive intermodulation) measurement techniques, and proven means of PIM reduction. Material and geometry considerations are examined. It is pointed out that PIM is an important consideration in high-channel-capacity communications systems. Ferrite materials and geometries with high current densities show particularly poor PIM performance. Environmental effects often degrade PIM performance. Although results are difficult to quantify, it is concluded that heeding a few basic design recommendations will decrease PIM levels.<>