A resonant DC-DC converter for generating high voltage bi-polar DC pulses, the resonant DC-DC converter comprising: a left multi-level resonant rectifier bank, including multiple left resonant rectifier stages (112, 114, 116), connected to a common node and to a positive electrode and coupled via capacitive isolation to a left radio frequency terminal; a right multi-level resonant rectifier bank, including multiple right resonant rectifier stages (118, 120, 122) associated with respectively opposing ones of the multiple left resonant rectifier stages (112, 114, 116), connected to the common node and to a negative electrode and coupled via capacitive isolation to a right RF terminal, the left and right RF terminals being driven by an RF voltage generator; each stage of the multiple left resonant rectifier stages and of the multiple right resonant rectifier stages including capacitors (166, 170; 168, 172) configured to capacitively isolate the stage, an output capacitor (154, 156), a switch (150, 152) configured to connect to an adjacent switch of an adjacent stage, wherein each switch includes a respective field-effect transistor, wherein the switch is activatable while energy from an opposing switch of the opposing resonant rectifier stage is causing energy to be delivered, and a gating resonant circuit, including a resonant inductor (124, 126; 178, 180), connected to the switch; wherein the inductors of each opposing right and left resonant rectifier stages are arranged via a conductive loop to form a coupled inductor pair with the switches of the associated gating resonant circuit thereby inducing an isolated voltage in the gating resonant circuit with one gating resonant circuit being used for each opposing switch; the switches in the left multi-level resonant rectifier bank and in the right multi-level resonant rectifier bank arranged to be controlled respectively in response to RF signals from the right and left RF terminals and arranged to cause the multi-level resonant rectifier banks to generate DC pulses of opposite polarity at respective ones of the electrodes. a left multi-level resonant rectifier bank, including multiple left resonant rectifier stages (112, 114, 116), connected to a common node and to a positive electrode and coupled via capacitive isolation to a left radio frequency terminal; a right multi-level resonant rectifier bank, including multiple right resonant rectifier stages (118, 120, 122) associated with respectively opposing ones of the multiple left resonant rectifier stages (112, 114, 116), connected to the common node and to a negative electrode and coupled via capacitive isolation to a right RF terminal, the left and right RF terminals being driven by an RF voltage generator; each stage of the multiple left resonant rectifier stages and of the multiple right resonant rectifier stages including capacitors (166, 170; 168, 172) configured to capacitively isolate the stage, an output capacitor (154, 156), a switch (150, 152) configured to connect to an adjacent switch of an adjacent stage, wherein each switch includes a respective field-effect transistor, wherein the switch is activatable while energy from an opposing switch of the opposing resonant rectifier stage is causing energy to be delivered, and a gating resonant circuit, including a resonant inductor (124, 126; 178, 180), connected to the switch; wherein the inductors of each opposing right and left resonant rectifier stages are arranged via a conductive loop to form a coupled inductor pair with the switches of the associated gating resonant circuit thereby inducing an isolated voltage in the gating resonant circuit with one gating resonant circuit being used for each opposing switch; the switches in the left multi-level resonant rectifier bank and in the right multi-level resonant rectifier bank arranged to be controlled respectively in response to RF signals from the right and left RF terminals and arranged to cause the multi-level resonant rectifier banks to generate DC pulses of opposite polarity at respective ones of the electrodes.