At least some embodiments are directed to a receiver system that comprises a first oscillation module configured to provide oscillating signals of differing frequencies and a second oscillation module configured to provide other oscillating signals of the differing frequencies. The second oscillation module is configured to produce less noise than the first oscillation module. A controller is coupled to the first and second oscillation modules and configured to selectively activate and deactivate each of the first and second oscillation modules based on signal strengths of primary signals received via a wireless medium and based on signal strengths of interference signals received via the wireless medium.

Systems and methods for adjusting power and frequency based on three or more states are described. One of the methods includes receiving a pulsed signal having multiple states. The pulsed signal is received by multiple radio frequency (RF) generators. When the pulsed signal having a first state is received, an RF signal having a pre-set power level is generated by a first RF generator and an RF signal having a pre-set power level is generated by a second RF generator. Moreover, when the pulsed signal having a second state is received, RF signals having pre-set power levels are generated by the first and second RF generators. Furthermore, when the pulsed signal having a third state is received, RF signals having pre-set power levels are generated by the first and second RF generators.

Systems and methods for adjusting power and frequency based on three or more states are described. One of the methods includes receiving a pulsed signal having multiple states. The pulsed signal is received by multiple radio frequency (RF) generators. When the pulsed signal having a first state is received, an RF signal having a pre-set power level is generated by a first RF generator and an RF signal having a pre-set power level is generated by a second RF generator. Moreover, when the pulsed signal having a second state is received, RF signals having pre-set power levels are generated by the first and second RF generators. Furthermore, when the pulsed signal having a third state is received, RF signals having pre-set power levels are generated by the first and second RF generators.

A phase locked loop includes a signal receiver configured to generate a mixed signal based on the received signal and an oscillator signal, and a frequency control circuit configured to compare the mixed signal to a reference signal, and adjust the oscillator signal based on a result of the comparing.

A phase locked loop includes a signal receiver configured to generate a mixed signal based on the received signal and an oscillator signal, and a frequency control circuit configured to compare the mixed signal to a reference signal, and adjust the oscillator signal based on a result of the comparing.

Systems and methods for adjusting power and frequency based on three or more states are described. One of the methods includes receiving a pulsed signal having multiple states. The pulsed signal is received by multiple radio frequency (RF) generators. When the pulsed signal having a first state is received, an RF signal having a pre-set power level is generated by a first RF generator and an RF signal having a pre-set power level is generated by a second RF generator. Moreover, when the pulsed signal having a second state is received, RF signals having pre-set power levels are generated by the first and second RF generators. Furthermore, when the pulsed signal having a third state is received, RF signals having pre-set power levels are generated by the first and second RF generators.

Systems and methods for adjusting power and frequency based on three or more states are described. One of the methods includes receiving a pulsed signal having multiple states. The pulsed signal is received by multiple radio frequency (RF) generators. When the pulsed signal having a first state is received, an RF signal having a pre-set power level is generated by a first RF generator and an RF signal having a pre-set power level is generated by a second RF generator. Moreover, when the pulsed signal having a second state is received, RF signals having pre-set power levels are generated by the first and second RF generators. Furthermore, when the pulsed signal having a third state is received, RF signals having pre-set power levels are generated by the first and second RF generators.

A charging apparatus includes a plurality of batteries, a changeover relay that can be changed over between a first state where the plurality of the batteries are connected in series to one another and a second state where the plurality of the batteries are connected in parallel to one another, an electric storage device, a main relay that is provided between the electric storage device and an electric load of a vehicle, and a control device that controls the opening/closing of the changeover relay. The control device renders the changeover relay in the first state when the main relay is in an open state.

Systems and methods for adjusting power and frequency based on three or more states are described. One of the methods includes receiving a pulsed signal having multiple states. The pulsed signal is received by multiple radio frequency (RF) generators. When the pulsed signal having a first state is received, an RF signal having a pre-set power level is generated by a first RF generator and an RF signal having a pre-set power level is generated by a second RF generator. Moreover, when the pulsed signal having a second state is received, RF signals having pre-set power levels are generated by the first and second RF generators. Furthermore, when the pulsed signal having a third state is received, RF signals having pre-set power levels are generated by the first and second RF generators.

Systems and methods for adjusting power and frequency based on three or more states are described. One of the methods includes receiving a pulsed signal having multiple states. The pulsed signal is received by multiple radio frequency (RF) generators. When the pulsed signal having a first state is received, an RF signal having a pre-set power level is generated by a first RF generator and an RF signal having a pre-set power level is generated by a second RF generator. Moreover, when the pulsed signal having a second state is received, RF signals having pre-set power levels are generated by the first and second RF generators. Furthermore, when the pulsed signal having a third state is received, RF signals having pre-set power levels are generated by the first and second RF generators.