Varactor bank switching based on negative control voltage generation

Abstract

A method and apparatus for varactor bank switching for a voltage controlled oscillator is disclosed. Varactor bank switching involves generating a negative bias voltage signal as a control signal for a varactor bank switch in an off-state, the varactor bank switch comprising a pass-gate circuit including switching transistors. Generating the negative bias voltage signal includes employing an active rectifier circuit running at the speed of an oscillation signal, the negative bias voltage signal maintaining the gate-source voltage of the pass-gate circuit below a threshold voltage to prevent said switching transistors from becoming conductive in an off-state.

1 . A system for varactor bank switching for an oscillator, comprising:
 a voltage controller configured for generating a negative bias voltage signal as a control signal for a varactor bank switch in an off-state, the varactor bank switch comprising a pass-gate circuit including switching transistors, the voltage controller comprising an active rectifier circuit configured for running at the speed of an oscillation signal, the negative bias voltage signal maintaining the gate-source voltage of the pass-gate circuit below a threshold voltage to prevent said switching transistors from becoming conductive in an off-state.