An oscillation maintenance circuit for a half-duplex transponder that has an LC resonant circuit, a storage capacitor and a rectifier connected to charge the storage capacitor with a rectified oscillation signal, having an end-of-burst detector providing an end-of-burst signal when the amplitude of the oscillation signal has dropped below a predetermined threshold. A clock regenerator provides a clock signal derived from the oscillation signal. Switching means controlled by the clock signal in the presence of the end-of-burst signal connect the storage capacitor with LC resonant circuit through at least one current limiting resistor during part of the period of the clock signal, in such a manner that energy is fed into the LC resonant circuit.