US Patent 11013075 RF apparatus with arc prevention using non-linear devices

An RF system includes an RF signal source and a single-ended or double-ended impedance matching network. Non-linear devices, such as gas discharge tubes, are coupled in parallel with components of the impedance matching network. The non-linear devices are insulating below a breakdown voltage and conductive above the breakdown voltage. The system also includes measurement circuitry configured to measure one or more parameters that reflect changes in the impedance of the impedance matching network. A system controller modifies operation of the system when a rate of change of any of the monitored parameter(s) exceeds a predetermined threshold.