An apparatus includes a tank circuit of a voltage controlled oscillator (VCO). A pair of alternating current (AC) coupling capacitors couple the gates of the pair of transistors to the drains of the pair of transistors. A bias circuit is coupled to the gates of the pair of transistors to bias the pair of transistors such that the pair of transistors alternatingly turn on during a plurality of peaks of an oscillating signal of the tank circuit and the pair of transistors turn off during a plurality of crossing points of the oscillating signal. A feedback loop may be configured to detect a peak oscillating amplitude of the oscillating signal and adjust a bias voltage of the bias circuit. Also, a supply capacitor may be coupled to the tank circuit and to the pair of transistors to provide an instantaneous current to the VCO.