System for wirelessly transmitting energy at a near-field distance without using beam-forming control
A method includes receiving an indication that a wireless-power receiver is located within one meter of a wireless-power transmission system and is authorized to receive wirelessly-delivered power from a wireless-power transmission system. The method includes, in response to receiving the indication, selecting a power level at which to amplify a radio frequency (RF) signal using a power amplifier (PA). In accordance with a determination that transmitting the RF signal to the wireless-power receiver would satisfy safety thresholds, the method includes instructing the PA to amplify the RF signal using the power level to create an amplified RF signal, and providing the amplified RF signal to the one or more antennas. The one or more antennas are caused to, upon receiving the amplified RF signal, radiate RF energy that is focused within an operating area that includes the wireless-power receiver while forgoing any active beamforming control.
1. A wireless-power transmission system, comprising:
one or more integrated circuits configured to:
receive an indication that a wireless-power receiver is located within one meter of the wireless-power transmission system and is authorized to receive wirelessly-delivered power from the wireless-power transmission system;
in response to receiving the indication, select a power level from among a plurality of available power levels at which to amplify a radio frequency (RF) signal using a power amplifier;
determine an operational impedance at the power amplifier based on an impedance measurement from among multiple measurement points of the power amplifier;
in accordance with a determination that transmitting the RF signal to the wireless-power receiver would satisfy one or more safety thresholds:
instruct the power amplifier to amplify the RF signal using the power level to create an amplified RF signal; and
provide the amplified RF signal to one or more antennas, wherein the one or more antennas are caused to, upon receiving the amplified RF signal, radiate RF energy that is focused within an operating area that includes the wireless-power receiver while forgoing any active beamforming control,
wherein the one or more safety thresholds include an impedance threshold indicating that the operational impedance is at a safe level, and the determination that transmitting the RF signal will satisfy the one or more safety thresholds is made when it is predicted that using the power level to amplify the RF signal would keep the operational impedance at the power amplifier within the impedance threshold.
2. The wireless-power transmission system of claim 1 , wherein the power level is a maximum power level from among the plurality of available power levels.
3. The wireless-power transmission system of claim 1 , wherein the wireless-power-transmission system includes only a single power amplifier and the one or more antennas include only a single antenna.
4. The wireless-power transmission system of claim 1 , wherein the one or more safety thresholds include a maximum specific absorption rate (SAR) value of not greater than 2 W/kg, and the determination that transmitting the RF signal would satisfy the one or more safety thresholds is made when it is determined that transmitting the RF signal would create a maximum SAR value of not greater than 2 W/kg at the wireless-power receiver.
5. The wireless-power transmission system of claim 4 , wherein the one or more safety thresholds include a maximum specific absorption rate (SAR) value of not greater than 0.8 W/kg, and the determination that transmitting the RF signal would satisfy the one or more safety thresholds is made when it is determined that transmitting the RF signal would create a maximum SAR value of not greater than 0.8 W/kg at the wireless-power receiver.
6. The wireless-power transmission system of claim 1 , wherein the one or more safety thresholds include a predetermined roll-off of 3 dB at a predetermined distance increment relative to a peak amount of RF energy produced by radiated RF energy, and the determination that transmitting the RF signal would satisfy the one or more safety thresholds is made when it is determined that transmitting the RF signal would create a peak amount of RF energy at the wireless-power receiver that has the predetermined roll-off of 3 dB for each predetermined distance increment relative to the peak amount of RF energy.
7. The wireless-power transmission system of claim 6 , wherein the predetermined distance increment is about 8 cm.
8. The wireless-power transmission system of claim 1 , wherein the one or more integrated circuits are further configured to:
receive an impedance measurement from among the multiple measurement points of the power amplifier;
utilize the impedance measurement to retrieve information for stored measurement values for two or more parametric parameters, the stored measurement values for the two or more parametric parameters indicating that the operational impedance is a safe operational impedance for the power amplifier; and
select the power level upon determining that the operational impedance is a safe operational impedance for the power amplifier.
9. The wireless-power transmission system of claim 1 , wherein the one or more integrated circuits are further configured to:
receive an impedance measurement from among multiple measurement points of the power amplifier;
utilize the impedance measurement to retrieve information for stored measurement values for two or more parametric parameters, the stored measurement values for the two or more parametric parameters indicating that the operational impedance is a safe operational impedance for the power amplifier;
determine a dissipation level corresponding to the retrieved information; and
select a decreased power level upon determining that the dissipation level is above a dissipation threshold, wherein the decreased power level is used to amplify the RF signal instead of the power level.
10. The wireless-power transmission system of claim 8 , wherein the power level is dynamically determined based on stored data retrieved from one or more data structures while the RF energy is focused within an operating area that includes the wireless-power receiver, and the system does not use any active beamforming control.
11. The wireless-power transmission system of claim 1 , wherein the one or more integrated circuits are configured to:
receive, from one or more sensors, a shut-off indication that indicates that an object is within a predefined shut-off distance of the wireless-power transmission system; and
in response to receiving the shut-off indication, cause the one or more antennas to cease radiating the RF energy.
12. The wireless-power transmission system of claim 11 , wherein the predefined shut-off distance is approximately 20 cm from the wireless-power transmission system.
13. The wireless-power transmission system of claim 1 , wherein the power level is selected from among the plurality of available power levels of the power amplifier when the wireless-power receiver is at most 40 cm from the wireless-power transmission system.
14. The wireless-power transmission system of claim 1 , wherein the power level is selected from among the plurality of available power levels of the power amplifier when the wireless-power receiver is within 20 cm to 40 cm from the wireless-power transmission system.
15. The wireless-power transmission system of claim 1 , wherein the power level is between 2 watts and 15 watts.
16. The wireless-power transmission system of claim 1 , wherein the one or more integrated circuits include a first integrated circuit and a second integrated circuit, wherein:
the first integrated circuit is configured to receive the indication that the wireless-power receiver is located within one meter of the wireless-power transmission system and is authorized to receive wireless charging from the wireless-power transmission system, and select the power level at which to generate the RF signal; and
the second integrated circuit is configured to control and manage one or more operations of the power amplifier including instructing the power amplifier to amplify the RF signal.
17. The wireless-power-transmission system of claim 1 , further comprising a communication radio coupled to the one or more integrated circuits, wherein:
the communication radio is configured to receive charging information from the wireless-power receiver; and
the one or more integrated circuits are configured to select the power level from among the plurality of available power levels based at least in part on the charging information.
18. A method, comprising:
receiving an indication that a wireless-power receiver is located within one meter of a wireless-power transmission system and is authorized to receive wirelessly-delivered power from the wireless-power transmission system;
in response to receiving the indication, selecting a power level from among a plurality of available power levels at which to amplify a radio frequency (RF) signal using a power amplifier;
determining an operational impedance at the power amplifier based on an impedance measurement from among multiple measurement points of the power amplifier;
in accordance with a determination that transmitting the RF signal to the wireless-power receiver would satisfy one or more safety thresholds:
instructing the power amplifier to amplify the RF signal using the power level to create an amplified RF signal; and
providing the amplified RF signal to one or more antennas, wherein the one or more antennas are caused to, upon receiving the amplified RF signal, radiate RF energy that is focused within an operating area that includes the wireless-power receiver while forgoing any active beamforming control,
wherein the one or more safety thresholds include an impedance threshold indicating that the operational impedance is at a safe level, and the determination that transmitting the RF signal will satisfy the one or more safety thresholds is made when it is predicted that using the power level to amplify the RF signal would keep the operational impedance at the power amplifier within the impedance threshold.
19. The method of claim 18 , wherein the power level is a maximum power level from among the plurality of available power levels.
20. The method of claim 18 , wherein the wireless-power-transmission system includes only a single power amplifier and the one or more antennas include only a single antenna.
21. The method of claim 18 , wherein the one or more safety thresholds include a maximum specific absorption rate (SAR) value of not greater than 2 W/kg, and the determination that transmitting the RF signal would satisfy the one or more safety thresholds is made when it is determined that transmitting the RF signal would create a maximum SAR value of not greater than 2 W/kg at the wireless-power receiver.
22. The method of claim 18 , wherein the one or more safety thresholds include a predetermined roll-off of 3 dB at a predetermined distance increment relative to a peak amount of RF energy produced by radiated RF energy, and the determination that transmitting the RF signal would satisfy the one or more safety thresholds is made when it is determined that transmitting the RF signal would create a peak amount of RF energy at the wireless-power receiver that has the predetermined roll-off of 3 dB for each predetermined distance increment relative to the peak amount of RF energy.
23. The method of claim 18 , further comprising:
receiving an impedance measurement from among multiple measurement points of the power amplifier;
utilizing the impedance measurement to retrieve information for stored measurement values for two or more parametric parameters, the stored measurement values for the two or more parametric parameters indicating that the operational impedance is a safe operational impedance for the power amplifier;
determining a dissipation level corresponding to the retrieved information; and
selecting a decreased power level upon determining that the dissipation level is above a dissipation threshold, wherein the decreased power level is used to amplify the RF signal instead of the power level.
24. A non-transitory, computer-readable medium storing instructions which, when executed by a processor in a computer, cause the computer to:
receive an indication that a wireless-power receiver is located within one meter of a wireless-power transmission system and is authorized to receive wirelessly-delivered power from the wireless-power transmission system;
in response to receiving the indication, select a power level from among a plurality of available power levels at which to amplify a radio frequency (RF) signal using a power amplifier;
determine an operational impedance at the power amplifier based on an impedance measurement from among multiple measurement points of the power amplifier;
in accordance with a determination that transmitting the RF signal to the wireless-power receiver would satisfy one or more safety thresholds:
instruct the power amplifier to amplify the RF signal using the power level to create an amplified RF signal; and
provide the amplified RF signal to one or more antennas, wherein the one or more antennas are caused to, upon receiving the amplified RF signal, radiate RF energy that is focused within an operating area that includes the wireless-power receiver while forgoing any active beamforming control,
wherein the one or more safety thresholds include an impedance threshold indicating that the operational impedance is at a safe level, and the determination that transmitting the RF signal will satisfy the one or more safety thresholds is made when it is predicted that using the power level to amplify the RF signal would keep the operational impedance at the power amplifier within the impedance threshold.
25. The non-transitory, computer-readable medium of claim 24 , wherein the power level is a maximum power level from among the plurality of available power levels.
26. The non-transitory, computer-readable medium of claim 24 , wherein the wireless-power-transmission system includes only a single power amplifier and the one or more antennas include only a single antenna.
27. The non-transitory, computer-readable medium of claim 24 , wherein the one or more safety thresholds include a maximum specific absorption rate (SAR) value of not greater than 2 W/kg, and the determination that transmitting the RF signal would satisfy the one or more safety thresholds is made when it is determined that transmitting the RF signal would create a maximum SAR value of not greater than 2 W/kg at the wireless-power receiver.
28. The non-transitory, computer-readable medium of claim 27 , wherein the one or more safety thresholds include a maximum specific absorption rate (SAR) value of not greater than 0.8 W/kg, and the determination that transmitting the RF signal would satisfy the one or more safety thresholds is made when it is determined that transmitting the RF signal would create a maximum SAR value of not greater than 0.8 W/kg at the wireless-power receiver.
29. The non-transitory, computer-readable medium of claim 24 , wherein the one or more safety thresholds include a predetermined roll-off of 3 dB at a predetermined distance increment relative to a peak amount of RF energy produced by radiated RF energy, and the determination that transmitting the RF signal would satisfy the one or more safety thresholds is made when it is determined that transmitting the RF signal would create a peak amount of RF energy at the wireless-power receiver that has the predetermined roll-off of 3 dB for each predetermined distance increment relative to the peak amount of RF energy.
30. The non-transitory, computer-readable medium of claim 29 , wherein the predetermined distance increment is about 8 cm.
31. The non-transitory, computer-readable medium of claim 24 , further comprising instructions which, when executed by the processor in the computer, further cause computer to:
receive an impedance measurement from among the multiple measurement points of the power amplifier;
utilize the impedance measurement to retrieve information for stored measurement values for two or more parametric parameters, the stored measurement values for the two or more parametric parameters indicating that the operational impedance is a safe operational impedance for the power amplifier; and
select the power level upon determining that the operational impedance is a safe operational impedance for the power amplifier.
32. The non-transitory, computer-readable medium of claim 24 , further comprising instructions which, when executed by the processor in the computer, further cause the computer to:
receive an impedance measurement from among multiple measurement points of the power amplifier;
utilize the impedance measurement to retrieve information for stored measurement values for two or more parametric parameters, the stored measurement values for the two or more parametric parameters indicating that the operational impedance is a safe operational impedance for the power amplifier;
determine a dissipation level corresponding to the retrieved information; and
select a decreased power level upon determining that the dissipation level is above a dissipation threshold, wherein the decreased power level is used to amplify the RF signal instead of the power level.
33. The non-transitory, computer-readable medium of claim 31 , wherein the power level is dynamically determined based on stored data retrieved from one or more data structures while the RF energy is focused within an operating area that includes the wireless-power receiver, and the system does not use any active beamforming control.
34. The non-transitory, computer-readable medium of claim 24 , further comprising instructions which, when executed by the processor in the computer, further cause the computer to:
receive, from one or more sensors, a shut-off indication that indicates that an object is within a predefined shut-off distance of the wireless-power transmission system; and
in response to receiving the shut-off indication, cause the one or more antennas to cease radiating the RF energy.
35. The non-transitory, computer-readable medium of claim 34 , wherein the predefined shut-off distance is approximately 20 cm from the wireless-power transmission system.
36. The non-transitory, computer-readable medium of claim 24 , wherein the power level is selected from among the plurality of available power levels of the power amplifier when the wireless-power receiver is at most 40 cm from the wireless-power transmission system.
37. The non-transitory, computer-readable medium of claim 24 , wherein the power level is selected from among the plurality of available power levels of the power amplifier when the wireless-power receiver is within 20 cm to 40 cm from the wireless-power transmission system.
38. The non-transitory, computer-readable medium of claim 24 , wherein the power level is between 2 watts and 15 watts.
39. The non-transitory, computer-readable medium of claim 24 , wherein:
a first integrated circuit is configured to receive the indication that the wireless-power receiver is located within one meter of the wireless-power transmission system and is authorized to receive wireless charging from the wireless-power transmission system, and select the power level at which to generate the RF signal; and
a second integrated circuit is configured to control and manage one or more operations of the power amplifier including instructing the power amplifier to amplify the RF signal.
40. The non-transitory, computer-readable medium of claim 24 , wherein the computer further comprises a communication radio and the non-transitory, computer-readable medium further comprises instructions which, when executed by the processor in the computer, further cause the computer to:
receive charging information from the wireless-power receiver; and
select the power level from among the plurality of available power levels based at least in part on the charging information.