Wireless power transmitter for high fidelity communications at high power transfer
Wireless power transfer systems, disclosed, include one or more circuits to facilitate high power transfer at high frequencies. Such wireless power transfer systems include a damping circuit, configured to dampen a wireless power signal such that communications fidelity is upheld at high power. The damping circuit includes at least a damping transistor that is configured to receive, from the transmitter controller, a damping signal for switching the transistor to control damping during transmission of the wireless data signals. Utilizing such systems enables wireless power transfer at high frequency, such as 13.56 MHz, at voltages over 1 Watt, while maintaining fidelity of in-band communications associated with the higher power wireless power signal.
1. A device comprising:
a transmitter antenna configured to couple with at least one other antenna and transmit alternating current (AC) wireless signals to the at least one other antenna, the AC wireless signals including wireless power signals and wireless data signals;
a transmitter controller that is configured to (i) provide a driving signal for driving the transmitter antenna based on an operating frequency for wireless power transfer and (ii) perform one or more of encoding the wireless data signals, decoding the wireless data signals, receiving the wireless data signals, or transmitting the wireless data signals;
an amplifier including at least one transistor that is configured to receive the driving signal at a gate of the at least one transistor and invert a direct power (DC) input power signal to generate the AC wireless signals at the operating frequency;
a transmitter tuning system connected in electrical parallel with the amplifier; and
a damping circuit configured to dampen the AC wireless signals during transmission of the wireless data signals, wherein the damping circuit includes at least a damping transistor that is configured to receive, from the transmitter controller, a damping signal for switching the damping transistor to control damping during transmission of the wireless data signals,
wherein the damping circuit is in a signal path of the device between the transmitter tuning system and the transmitter antenna.
2. The device of claim 1 , wherein the wireless data signals are in-band signals of the wireless power signals and the damping of the AC wireless signals is configured to reduce one or both of rise and fall times in the wireless data signals, during in-band transmission of the wireless data signals.
3. The device of claim 2 , wherein the wireless data signals are in-band on-off-keying signals of the wireless power signals.
4. The device of claim 3 , wherein the damping signal is a substantially opposite signal of the wireless data signals.
5. The device of claim 2 , wherein the wireless data signals are in-band amplitude shift keying signals of the wireless power signals.
6. The device of claim 1 , wherein the damping circuit further includes a damping resistor that is in electrical series with the damping transistor and is configured for dissipating at least some power from the wireless power signals.
7. The device of claim 1 , wherein the damping circuit further includes a damping capacitor that is in electrical series with, at least, the damping transistor.
8. The device of claim 1 , wherein the damping circuit further includes a diode that is in electrical series with, at least, the damping transistor and is configured for preventing power efficiency loss in the wireless power signals when the damping circuit is not active.
9. A device comprising:
a transmitter antenna configured to couple with at least one other antenna and transmit alternating current (AC) wireless signals to the at least one other antenna, the AC wireless signals including wireless power signals and wireless data signals;
a transmitter controller that is configured to (i) provide a driving signal for driving the transmitter antenna based on an operating frequency for wireless power transfer and (ii) perform one or more of encoding the wireless data signals, decoding the wireless data signals, receiving the wireless data signals, or transmitting the wireless data signals;
an amplifier, the amplifier including at least one transistor that is configured to receive the driving signal at a gate of the at least one transistor and invert a direct power (DC) input power signal to generate the AC wireless signals at the operating frequency;
a transmitter tuning system in electrical connection with the amplifier; and
a damping circuit that is configured to dampen the AC wireless signals during transmission of the wireless data signals, wherein the damping circuit includes at least a damping transistor that is configured to receive, from the transmitter controller, a damping signal for switching the damping transistor to control damping during transmission of the wireless data signals, the damping circuit connected in electrical parallel with the transmitter antenna.
10. The device of claim 9 , wherein the wireless data signals are in-band signals of the wireless power signals and the damping of the AC wireless signals is configured to reduce one or both of rise and fall times in the wireless data signals, during in-band transmission of the wireless data signals.
11. The device of claim 10 , wherein the wireless data signals are in-band on-off-keying signals of the wireless power signals.
12. The device of claim 11 , wherein the damping signal is a substantially opposite signal of the wireless data signals.
13. The device of claim 10 , wherein the wireless data signals are in-band amplitude shift keying signals of the wireless power signals.
14. The device of claim 9 , wherein the damping circuit further includes a damping resistor that is in electrical series with the damping transistor and is configured for dissipating at least some power from the wireless power signals.
15. The device of claim 9 , wherein the damping circuit further includes a damping capacitor that is in electrical series with, at least, the damping transistor.
16. The device of claim 9 , wherein the damping circuit further includes a diode that is in electrical series with, at least, the damping transistor and is configured for preventing power efficiency loss in the wireless power signals when the damping circuit is not active.
17. A charger for a Near-Field Communications Direct Charge (NFC-DC) system comprising:
a transmitter antenna configured to couple with at least one other antenna and transmit alternating current (AC) wireless signals to the at least one other antenna, the AC wireless signals including wireless power signals and wireless data signals;
a transmitter controller that is configured to (i) provide a driving signal for driving the transmitter antenna based on an operating frequency for the NFC-DC system and (ii) perform one or more of encoding the wireless data signals, decoding the wireless data signals, receiving the wireless data signals, or transmitting the wireless data signals;
an amplifier, the amplifier including at least one transistor that is configured to receive the driving signal at a gate of the at least one transistor and invert a direct current (DC) input power signal to generate the AC wireless signals at the operating frequency;
a transmitter tuning system in electrical parallel with the amplifier; and
a damping circuit configured for damping the AC wireless signals during transmission of the wireless data signals, the damping circuit including, at least, a damping transistor configured for receiving a damping signal from the transmitter controller, the damping signal configured for switching the damping transistor to control damping during transmission of the wireless data signals,
wherein the damping circuit is in a signal path of the charger between the transmitter tuning system and the transmitter antenna.
18. The charger of claim 17 , wherein the damping circuit is in electrical connection with the transmitter antenna.
19. The charger of claim 17 , wherein the damping circuit is connected in electrical parallel with the transmitter antenna.
20. The charger of claim 17 , wherein the operating frequency is in a range of about 13.553 megahertz (MHz) to about 13.567 MHz.