Robust foreign objects detection
AssigneeMediatek Inc.
InventorsVladimir Alexander Muratov, Patrick Stanley Riehl, William Plumb
Life of this patent
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Abstract
An apparatus and method for performing foreign object detection for a wireless power transmitter. A matching network and transmit coil are energized, and a resonance is excited. The resonance is allowed to decay. A temporal characteristic of the decay is measured. The temporal characteristic is analyzed to determine whether a foreign object is coupled to an electromagnetic field generated by the transmit coil.
Claims20
A foreign object detection method for a wireless power transmitter having a matching network and transmit coil, the method comprising:
- (A) energizing the matching network and transmit coil and exciting resonance between the matching network and transmit coil;
- (B) allowing the resonance to decay;
- (C) detecting an envelope of an electrical parameter of the matching network or transmit coil as the resonance decays;
- (D) determining a quality factor using the envelope;
- and
- (E) analyzing the quality factor to determine whether a foreign object is coupled to an electromagnetic field generated by the transmit coil.
At least one non-transitory computer readable storage medium having stored thereon instructions, which, when executed by a processor, perform a foreign object detection method for a wireless power transmitter having a matching network and transmit coil, the foreign object detection method comprising:
- (A) energizing the matching network and transmit coil and exciting resonance between the matching network and transmit coil;
- (B) allowing the resonance to decay;
- (C) detecting an envelope of an electrical parameter of the matching network or transmit coil as the resonance decays;
- (D) determining a quality factor using the envelope;
- and
- (E) analyzing the quality factor to determine whether a foreign object is coupled to an electromagnetic field generated by the transmit coil.
An apparatus for performing foreign object detection for a wireless power transmitter having a matching network and transmit coil, the apparatus comprising:
- circuitry configured to:
- (A) energize the matching network and transmit coil and exciting resonance between the matching network and transmit coil;
- (B) allow the resonance to decay;
- (C) detect an envelope of an electrical parameter of the matching network or transmit coil as the resonance decays;
- (D) determine a quality factor using the envelope;
- and
- (E) analyze the quality factor to determine whether a foreign object is coupled to an electromagnetic field generated by the transmit coil.
An apparatus for driving a wireless power transmitter and performing foreign object detection, the apparatus comprising:
- a drive circuit configured to energize a matching network and transmit coil of the wireless power transmitter, excite resonance between the matching network and transmit coil, and allow the resonance to decay;
- and
- a controller configured to control the drive circuit, detect an envelope of an electrical parameter of the matching network or transmit coil as the resonance decays, determine a quality factor using the envelope, and analyze the quality factor to determine whether a foreign object is coupled to an electromagnetic field generated by the transmit coil.
Dependencies are inferred from the claim text.