Understanding And Mitigating Multipaction

When developing mission-critical space applications such as low Earth orbit (LEO) satellites or equipment designed for Mars missions, there are special considerations you must make if you will be operating your RF circuits in a vacuum. This is because when pressure in the vacuum is below 10-2 Torr, a potentially catastrophic phenomenon in RF circuits called multipaction is possible.

What Is Multipaction and What Causes It?

In short, multipaction is an electron resonance effect that can occur when free electrons present in a vacuum accelerate and impact a surface. It is common to have free electrons present in an RF device either between conducting surfaces or if the electrons are ejected from the surface dielectric through the strength of the RF field. These free electrons can then be subjected to acceleration by the RF field.