This paper presents a preliminary work on the feeding of an AC dipole using a resonant circuit with a varying resonant frequency. A single phase LC oscillator containing a variable capacitor is fed by a wide band amplifier or a voltage source inverter. For this purpose, a bank of switched capacitors of different values are connected to the main circuit through bidirectional switches. In order to allow zero-current and zerovoltage switching, the devices are implemented with close-control driver circuits allowing self-switching based on local polarity measurements. An innovative controller for maintaining the current in an oscillator and a regressive method for measuring alternating current with a limited number of samples are proposed and validated by experiment.