Methods and apparatus for testing of wireless power transmitters and systems

Patent metadata

Field	Value
Publication number	US-2016103191-A1
Application number	US-201514876719-A
Country	US
Kind code	A1
Filing date	Oct 6, 2015
Priority date	Oct 8, 2014
Publication date	Apr 14, 2016
Grant date	—

Abstract

This disclosure provides methods and apparatus for wireless power field testing. A method for generating testing the interoperability of a wireless power transmitter with one or more wireless power receivers is provided. The method includes generating a magnetic field via a transmit antenna. The method further includes measuring a first uniformity of the magnetic field at all the locations within the magnetic field on a charging surface of the wireless power transmitter. The method also includes determining that the measure first uniformity of the magnetic field is within a range of values at all locations on the charging surface of the wireless power transmitter. In some implementations, the method further includes applying a load to the magnetic field, measuring a second uniformity of the magnetic field while the load is applied, and determining if the first uniformity of the magnetic field is substantially similar to the second uniformity.

First claim

What is claimed is:

1 . A method of testing a wireless power transmitter, comprising:
generating a magnetic field via a transmit antenna; identifying a first uniformity level of the magnetic field based on a comparison of a plurality of measurements of the magnetic field at a plurality of locations on a charging surface of the wireless power transmitter; and comparing the plurality of measurements of the magnetic field with a predetermined range of values for the plurality of locations on the charging surface of the wireless power transmitter, where the magnetic field is determined to be uniform if the plurality of measurements of the magnetic field are within the predetermined range of values for a majority of the plurality of locations on the charging surface.

2 . The method of claim 1 , further comprising:
presenting a load to the transmit antenna within an area; identifying a second uniformity level of the magnetic field while the load is presented to the transmit antenna based on another comparison of another plurality of measurements of the magnetic field at locations of the plurality of locations outside of the area; and comparing the plurality of measurements of the magnetic field with the other plurality of measurements of the magnetic field after the load is presented to the transmit antenna to determine if the first and second uniformity levels at corresponding locations are within a threshold range of each other.

3 . The method of claim 2 , wherein presenting a load to the transmit antenna comprises presenting a resistive load to the transmit antenna within the magnetic field, and wherein comparing the plurality of measurements of the magnetic field with the other plurality of measurements of the magnetic field comprises comparing the plurality of measurements with the other plurality of measurements to determine whether the wireless power transmitter is able to maintain the magnetic field within a range at or above a threshold after the resistive load is applied to the wireless power transmitter within the magnetic field.

4 . The method of claim 3 , wherein the resistive load presented is presented via an external device, and wherein the external device is configured to vary the resistive load from a minimum value to a maximum value.

5 . The method of claim 3 , wherein presenting a resistive load to the transmit antenna comprises presenting a plurality of resistive loads to the transmit antenna.

6 . The method of claim 2 , wherein presenting the load comprises presenting an adjustable amount of reactance shift at the transmit antenna of the wireless power transmitter, and wherein comparing the plurality of measurements with the other plurality of measurements comprises comparing the pluralities of measurements to determine whether the wireless power transmitter is able to maintain the magnetic field within the range of values after the reactance shift is adjusted.

7 . The method of claim 6 , wherein the adjustable amount of reactance shift is adjusted to be at least one of more capacitive or more inductive.

8 . The method of claim 2 , wherein presenting the load to the transmit antenna comprises presenting a plurality of adjustable, resistive loads to the transmit antenna.

9 . The method of claim 1 , wherein identifying a first uniformity level of the magnetic field comprises identifying the first uniformity level of the magnetic field based on a comparison of a plurality of open circuit voltage measurements of the magnetic field at the plurality of locations on the charging surface of the wireless power transmitter.

10 . The method of claim 1 , wherein the plurality of locations comprises all locations of the charging surface such that the plurality of measurements of the magnetic field comprises measurements of the magnetic field at all locations of the charging surface of the wireless power transmitter.

11 . A method of testing a wireless power transmitter, comprising:
generating a magnetic field via a transmit antenna; measuring a plurality of values indicative of a magnitude of the magnetic field at a plurality of locations of a charging surface of the wireless power transmitter; and determining that the plurality of values indicative of the magnitude of the magnetic field is within a predetermined range of values at the plurality of locations.

12 . The method of claim 11 , wherein the plurality of values comprises a plurality of open circuit voltages of a test circuit configured to be selectively positioned at the plurality of locations.

13 . The method of claim 11 , further comprising:
presenting a load to the transmit antenna at an area via an external device configured to couple to the magnetic field; measuring another plurality of values indicative of the magnitude of the magnetic field at locations of the plurality of locations outside the area; and determining that the other plurality of values are within the predetermined range of values.

14 . The method of claim 13 , wherein values of the other plurality of values after the external device is presented to the transmit antenna are within a threshold range of corresponding values of the plurality of values prior to the external device being presented to the transmit antenna.

15 . The method of claim 11 , further comprising:
adjusting a resistance presented to the transmit antenna via an external device configured to couple to the magnetic field across a pre-determined range of resistances; measuring another plurality of values indicative of the magnitude of the magnetic field at another plurality of locations where the external device is not presented to the transmit antenna as the resistance is adjusted across the pre-determined range of resistances; and determining that the plurality of values are within the predetermined range of values.

16 . The method of claim 11 , further comprising:
adjusting a resistance presented to the transmit antenna via a plurality of external devices configured to couple to the magnetic field across a pre-determined range of resistances; measuring another plurality of values indicative of the magnitude of the magnetic field at another plurality of locations where the plurality of external devices are not presented to the transmit antenna as the resistance is adjusted across the pre-determined range of resistances; and determining that the plurality of values are within the predetermined range of values.

17 . The method of claim 11 , further comprising:
adjusting a reactance shift presented to the transmit antenna via an external device configured to couple to the magnetic field across a pre-determined range of reactance shifts; measuring another plurality of values indicative of the magnitude of the magnetic field at another plurality of locations where the external device is not presented to the transmit antenna as the reactance shift is adjusted across the pre-determined range of reactance shifts; and determining that the plurality of values are within the predetermined range of values.

18 . The method of claim 11 , further comprising:
adjusting a reactance shift presented to the transmit antenna via a plurality of external devices configured to couple to the magnetic field across a pre-determined range of reactance shifts; measuring another plurality of values indicative of the magnitude of the magnetic field at another plurality of locations where the plurality of external devices are not presented to the transmit antenna as the reactance shift is adjusted across the pre-determined range of

Assignees

• Qualcomm Inc

Inventors

• Von Novak Iii William Henry
• Chi Mei-Li

Classifications

• G01R29/10

  Radiation diagrams of antennas · CPC title

• G01R29/0892 Primary

  Details related to signal analysis or treatment; presenting results, e.g. displays; measuring specific signal features other than field strength, e.g. polarisation, field modes, phase, envelope, maximum value · CPC title

• G01R33/02 Primary

  Measuring direction or magnitude of magnetic fields or magnetic flux (G01R33/20 takes precedence) · CPC title

• G01R33/10

  Plotting field distribution {; Measuring field distribution} · CPC title

• H02J7/025

  Electricity · mapped topic