Robust foreign objects detection
AssigneeMediatek Inc.
InventorsVladimir A. 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.
Claims18
A foreign object detection method for a wireless power transmitter having a matching network and transmit coil, the method comprising:
- measuring a quality factor of the transmit coil;
- and
- analyzing the quality factor to determine whether a foreign object is coupled to an electromagnetic field generated by the transmit coil,
- wherein the wireless power transmitter transfers sufficient energy to a wireless power receiver to charge a rectifier filter capacitor of the wireless power receiver and reverse bias rectifier diodes of the wireless power receiver.
A foreign object detection method for a wireless power transmitter having a matching network and transmit coil, the method comprising:
- energizing the matching network and transmit coil and exciting resonance between the matching network and transmit coil;
- measuring a quality factor of the transmit coil;
- and
- comparing the quality factor to a threshold 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 controller configured to measure a quality factor of a transmit coil of the wireless power transmitter and analyze the quality factor to determine whether a foreign object is coupled to an electromagnetic field generated by the transmit coil,
- wherein wireless power transmitter transfers sufficient energy to a wireless power receiver to charge a rectifier filter capacitor of the wireless power receiver and reverse bias rectifier diodes of the wireless power receiver.
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 and excite resonance between the matching network and transmit coil;
- and
- a controller configured to measure a quality factor of the transmit coil and analyze the quality factor by comparing the quality factor to a threshold to determine whether a foreign object is coupled to an electromagnetic field generated by the transmit coil.
Dependencies are inferred from the claim text.