DUAL-MODE WIRELESS POWER TRANSFER APPARATUS

• US 20160261148A1
• Filed: 05/16/2016
• Published: 09/08/2016
• Est. Priority Date: 08/03/2012
• Status: Active Grant

• Current Assignee: MediaTek Singapore Pte. Ltd. (MediaTek, Inc.)
• Original Assignee: MediaTek Singapore Pte. Ltd. (MediaTek, Inc.)
• Inventors: Riehl, Patrick Stanley
• Granted Patent: US 9,893,567 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices

Abstract

A dual-mode receiver is provided that includes an electromagnetic resonator having one or more inductive elements that are arranged to form a receiver coil and a network of passive components arranged to form a matching network. The electromagnetic resonator includes a first selective frequency defined in a low frequency range and a second selective frequency defined in a high frequency range allowing for a rectification circuit to operate in both the high frequency range and low frequency range making maximum use of active circuits.

Claims

1. A wireless power transfer apparatus, comprising:

a plurality of wireless power transfer coils including a first wireless power transfer coil to transfer power wirelessly at a first frequency and a second wireless power transfer coil to transfer power wirelessly at a second frequency; and

a passive network coupled to the first and second wireless power transfer coils, the passive network and first wireless power transfer coil having a first resonance at the first frequency, the passive network and second wireless power transfer coil having a second resonance at the second frequency.

2. The wireless power transfer apparatus of claim 1, wherein the first frequency is lower than the second frequency by a factor of at least five.

3. The wireless power transfer apparatus of claim 1, wherein the second frequency is within the ISM band.

4. The wireless power transfer apparatus of claim 1, wherein the first frequency is between 100 kHz and 200 kHz and the second frequency is 6.78 MHz.

5. The wireless power transfer apparatus of claim 1, wherein the passive network comprises a plurality of capacitors.

6. The wireless power transfer apparatus of claim 1, wherein the first wireless power transfer coil and the second wireless power transfer coil are in series with one another.

7. The wireless power transfer apparatus of claim 6, wherein the passive network comprises a capacitor having a terminal coupled between the first wireless power transfer coil and the second wireless power transfer coil.

8. The wireless power transfer apparatus of claim 1, wherein the first and second wireless power transfer coils are concentric.

9. The wireless power transfer apparatus of claim 1, wherein the first and second wireless power transfer coils are planar.

10. The wireless power transfer apparatus of claim 1, further comprising:

a plurality of switching elements coupled to the passive network to convert between AC and DC.

11. The wireless power transfer apparatus of claim 10, wherein the plurality of switching elements converts from AC to DC.

12. The wireless power transfer apparatus of claim 1, wherein the wireless power transfer apparatus is a wireless power receiver.

13. The wireless power transfer apparatus of claim 1, wherein the wireless power transfer apparatus is a multi-mode wireless power transfer apparatus configured to transfer power wirelessly at the first frequency or the second frequency.

14. The wireless power transfer apparatus of claim 1, wherein the passive network is a matching network.

15. The wireless power transfer apparatus of claim 1, wherein the wireless power transfer apparatus is configured to provide in-band communications based on load modulation.

16. A wireless power transfer method, comprising:

transferring power wirelessly at a first frequency through a first wireless power transfer coil and a passive network, the first wireless power transfer coil and passive network having a first resonance at the first frequency; and

transferring power wirelessly at a second frequency through a second wireless power transfer coil and the passive network, the second wireless power transfer coil and passive network having a second resonance at the second frequency.

17. The wireless power transfer method of claim 16, wherein the first frequency is lower than the second frequency by a factor of at least five.

18. The wireless power transfer method of claim 16, wherein the first frequency is between 100 kHz and 200 kHz and the second frequency is 6.78 MHz.