Abstract:
An apparatus for optimizing a quality factor Q associated with an electrical resonator system includes an LC resonator and an optimizing circuit for providing a negative resistance. The optimizing circuit is electrically coupled to the resonator circuit, and includes two CMOS transistor pairs with the gates of the PMOS transistors cross-coupled with inputs to the resonator through capacitors, and the gates of the NMOS transistor cross-coupled with the inputs to the resonator through capacitors. The optimizing circuit receives at least one control voltage for varying the negative resistance by selectively biasing the PMOS transistors and NMOS transistors. The optimizing circuit also includes a current source for providing a controlled current to the CMOS transistor pairs. The current source is situated either between a supply voltage and the CMOS transistor pairs, or between the CMOS transistor pairs and a ground reference voltage. A current-control voltage controls the current flowing through the CMOS transistor pairs.
Abstract:
An apparatus for optimizing a quality factor Q associated with an electrical resonator system includes an LC resonator and an optimizing circuit for providing a negative resistance. The optimizing circuit is electrically coupled to the resonator circuit, and includes two CMOS transistor pairs with the gates of the PMOS transistors cross-coupled with inputs to the resonator through capacitors, and the gates of the NMOS transistor cross-coupled with the inputs to the resonator through capacitors. The optimizing circuit receives at least one control voltage for varying the negative resistance by selectively biasing the PMOS transistors and NMOS transistors. The optimizing circuit also includes a current source for providing a controlled current to the CMOS transistor pairs. The current source is situated either between a supply voltage and the CMOS transistor pairs, or between the CMOS transistor pairs and a ground reference voltage. A current-control voltage controls the current flowing through the CMOS transistor pairs.