A system for generating a radio frequency (RF) signal at a drive frequency and a high voltage. The system includes a RF amplifier to amplify the voltage of a drive signal having a selected RF frequency. The amplified drive signal is used to drive a resonator to generate the RF signal such that the resonant frequency is the same or substantially the same as the drive frequency. A resonance tuning controller compares the drive frequency and the resonant frequency. If the resonant frequency and drive frequency are different, a temperature changing element is controlled to either increase heat or decrease heat radiating toward a tuning component with a resonance parameter that varies with temperature. For example, the heat may change the capacitance of the tuning capacitor causing a change in the resonant frequency of the resonator.