What PIM is
Passive intermodulation is unwanted mixing that occurs when two or more signals pass through nonlinear passive components. The result is new frequencies that can fall inside a receive band.
Why it matters
- PIM creates interference that is hard to filter later.
- It degrades receiver sensitivity and uplink capacity.
- Poor match quality makes it worse — reflections add junctions where products can form.
- It is a top concern in high-power, multi-carrier systems.
Common sources
- Poor or corroded metal-to-metal contacts.
- Ferromagnetic materials and plating defects.
- Contamination and mechanical stress.
- Overloaded connectors and junctions.
How to reduce it
- Choose low-PIM RF components rated for your carrier configuration.
- Keep connectors clean and properly torqued.
- Avoid ferromagnetic materials in high-power paths.
- Specify low-PIM finishes for critical interconnects.
RFPro advice
If your system carries multiple carriers at high power, make low-PIM components a hard requirement up front.