Radio frequency gas breakdown and micro/nano-plasma formation in high-power evanescent-mode cavity resonators

Microwave gas breakdown may limit power handling in antennas and RF resonators that store electromagnetic energy in micro/nano-gaps. In this paper, we review the numerical modeling and experimental validation of RF gas breakdown in evanescent-mode cavity resonators. This type of resonator stores the majority of its electric field energy in a micron-sized gap. High RF power-induced gas breakdown may degrade its performance by shifting the resonant frequency and/or increasing its insertion loss by eroding the micron-size-gap forming electrodes. Both static and tunable resonators are studied by RF plasma simulation techniques and the results are experimentally validated by high power measurements.