US Patent 11670488 Fast arc detecting match network

A method of detecting plasma asymmetry in a radio frequency plasma processing system, the method including providing a radio frequency power to a reaction chamber having an approximate chamber symmetry axis and receiving from a plurality of broadband electromagnetic sensors a radio frequency signal. The method also including processing the radio frequency signals using Fourier analysis and determining based on the Fourier analysis of the radio frequency signals that a plasma asymmetry has occurred within the reaction chamber.