Fundamentals and ignition of a microplasma at 2.45 GHz

This paper presents the fundamentals of a microplasma ignition and a patented coaxial system for ignition at atmospheric pressure with low RF power. The idea is to transform the voltage of the RF signal by a transformer and a resonator. Due to the fact that this coaxial structure realizes a very high impedance transformation, a microplasma at 2.45 GHz can be ignited and sustained with a 50 W microwave source. With this concept a magnitude of 30 MVm^-1 is realized at the electrode, which sufficiently increasing the kinetic energy of the free electrons to ionize air and resulting in a plasma sphere with a diameter of 6 mm.