The impact of passive intermodulation on specifying and characterising components

Communications systems are continually being required to improve on their transmit power capability as well as receiver sensitivity in order to meet the increasing user demand. These demands are consequently placing more stringent RF performance requirements on many system components, in particular their Passive InterModulation (PLM) performance. This paper reviews the implications of the quality of a selection of surface finishes commonly found on component hardware following the successful completion of a recent research study completed under contract to ESTEC. The key parameters relevant to defining a standard test methodology allowing components to be characterised for their PIM performance in a consistent manner is also described as way of an introduction to the subject of Passive Intermodulation.