Power transfer device and method

1. A device comprising:

a power transfer device for charging a wireless communication device having a communication bandwidth, the power transfer device transferring power at a transfer frequency using a spread-spectrum technique to reduce or minimize interference signals within the communication bandwidth, wherein the spread-spectrum technique utilizes a direct sequence spread-spectrum method implemented with a microprocessor control unit and a voltage controlled oscillator; wherein, the microprocessor control unit has a clock frequency and generates switching control signals for power inverter in the power transfer device, the direct sequence spread-spectrum method including storing a pseudo-random sequence in the microprocessor control unit and sending out the pseudorandom sequence to modulate the clock frequency through the voltage controlled oscillator.

2. A power transfer device according to claim 1 wherein the spread-spectrum technique reduces or minimizes the concentration of the interference signals.

3. A power transfer device according to claim 1 wherein the spread-spectrum technique reduces or minimizes the magnitude of at least one of the interference signals.

4. A power transfer device according to claim 1 wherein the spread-spectrum technique reduces or minimizes the average power of the interference signals.

5. A power transfer device according to claim 1 wherein power is transferred by switching and the spread-spectrum technique varies at least one of the characteristics of the switching.

6. A power transfer device according to claim 5 wherein the spread-spectrum technique varies at least one of switching frequency, switching pulse width, and switching pulse position.

7. A power transfer device according to claim 1 wherein the spread-spectrum technique is at least one of dithering, pseudo-random, random, chaotic, and modulated type, and thereby varies the transfer frequency.

8. A power transfer device according to claim 1 wherein the spread-spectrum technique varies the transfer frequency within a transfer bandwidth that maximizes the energy efficiency of the power transfer of the power transfer device.

9. A power transfer device according to claim 1 wherein the spread-spectrum technique utilizes at least one of variable pulse-position modulation, variable pulse-width modulation, variable carrier-frequency modulation with fixed duty cycle, and variable carrier-frequency modulation with variable duty cycle.

10. A power transfer device according to claim 1 wherein the spread-spectrum technique utilizes a frequency hopping spread-spectrum method.

11. A power transfer device according to claim 1 wherein the microprocessor control unit has an internal reference clock signal or an external reference clock signal.

12. A power transfer device according to claim 1 wherein the voltage controlled oscillator is implemented with two varactors.

13. A power transfer device according to claim 1 wherein the power transfer device wirelessly charges the wireless communication device.

14. A power transfer device according to claim 13 wherein the power transfer device wirelessly charges the wireless communication device using induction.

15. A power transfer device according to claim 1 wherein the communication bandwidth is located between 800 MHz and 1900 MHz.

16. A power transfer device according to claim 1 wherein the transfer frequency is less than the magnitude of the communication bandwidth.

17. A power transfer device according to claim 1 wherein the spread-spectrum technique reduces or minimizes interference within the power transfer device.

18. A device comprising:

a power transfer device for charging a wireless communication device having a communication bandwidth, the power transfer device transferring power at a transfer frequency, wherein either: the transfer frequency is selected to be greater than or equal to the magnitude of the communication bandwidth; or the transfer frequency is selected to be less than the magnitude of the communication bandwidth and the power transfer device transfers power using a spread-spectrum technique to reduce or minimize interference signals within the communication bandwidth, wherein the spread-spectrum technique utilizes a direct sequence spread-spectrum method implemented with a microprocessor control unit and a voltage controlled oscillator; wherein, the microprocessor control unit has a clock frequency and generates switching control signals for power inverter in the power transfer device, the direct sequence spread-spectrum method including storing a pseudo-random sequence in the microprocessor control unit and sending out the pseudo-random sequence to modulate the clock frequency through the voltage controlled oscillator.

19. A method comprising:

transferring power to a wireless communication device having a communication bandwidth, the method including using a spread-spectrum technique to transfer power at a transfer frequency to reduce or minimize interference signals within the communication bandwidth, wherein the spread-spectrum technique utilizes a direct sequence spread-spectrum method implemented with a microprocessor control unit and a voltage controlled oscillator; wherein, the microprocessor control unit has a clock frequency and generates switching control signals for power inverter in the power transfer device, the direct sequence spread-spectrum method including storing a pseudo-random sequence in the microprocessor control unit and sending out the pseudo-random sequence to modulate the clock frequency through the voltage controlled oscillator.

20. A method according to claim 19 wherein the spread-spectrum technique is used to reduce or minimize the concentration of the interference signals.

21. A method according to claim 19 wherein the spread-spectrum technique is used to reduce or minimize the magnitude of at least one of the interference signals.

22. A method according to claim 19 wherein the spread-spectrum technique is used to reduce or minimize the average power of the interference signals.

23. A method according to claim 19 including using switching to transfer power and the spread-spectrum technique is used to vary at least one of the characteristics of the switching.

24. A method according to claim 23 wherein the spread-spectrum technique is used to vary at least one of switching frequency, switching pulse width, and switching pulse position.

25. A method according to claim 19 wherein the spread-spectrum technique is at least one of dithering, pseudo-random, random, chaotic, and modulated type, and is thereby used to vary the transfer frequency.

26. A method according to claim 19 wherein the spread-spectrum technique is used to vary the transfer frequency within a transfer bandwidth that maximizes the energy efficiency of the power transfer.

27. A method according to claim 19 wherein the spread-spectrum technique utilizes at least one of variable pulse-position modulation, variable pulse-width modulation, variable carrier-frequency modulation with fixed duty cycle, and variable carrier-frequency modulation with variable duty cycle.

28. A method according to claim 19 wherein the spread-spectrum technique utilizes a frequency hopping spread-spectrum method.

29. A method according to claim 19 wherein the microprocessor control unit has an internal reference clock signal or an external reference clock signal.

30. A method according to claim 19 wherein the voltage controlled oscillator is implemented with two varactors.

31. A method according to claim 19 wherein power is transferred to wirelessly charge the wireless communication device.

32. A method according to claim 31 wherein power is transferred using induction to wirelessly charge the wireless communication device.

33. A method according to claim 19 wherein the communication bandwidth is located between 800 MHz and 1900 MHz.

34. A method according to claim 19 wherein the transfer frequency is less than the magnitude of the communication bandwidth.

35. A method according to claim 19 wherein a power transfer device is used to transfer power and the spread-spectrum technique is used to reduce or minimize interference within the power transfer device.

36. A method comprising:

transferring power to a wireless communication device having a communication bandwidth, the method including selecting to either: transfer power at a transfer frequency greater than or equal to the magnitude of the communication bandwidth; or use a spread-spectrum technique to transfer power at a transfer frequency less than the communication bandwidth to reduce or minimize interference signals within the communication bandwidth, wherein the spread-spectrum technique utilizes a direct sequence spread-spectrum method implemented with a microprocessor control unit and a voltage controlled oscillator; wherein, the microprocessor control unit has a clock frequency and generates switching control signals for power inverter in the power transfer device, the direct sequence spread-spectrum method including storing a pseudo-random sequence in the microprocessor control unit and sending out the pseudo-random sequence to modulate the clock frequency through the voltage controlled oscillator.