Wireless charging foreign object detection

An inductive wireless charger, comprising:

• a microcontroller;
• a charging surface;
• a charging source coil in communication with the microcontroller to generate a first magnetic field;
• a near-field communication (NFC) coil to generate a second magnetic field;
• and
• a near-field communication (NFC) chip in communication with the NFC coil, the NFC chip configured to determine a vector impedance of the NFC coil, the determined vector impedance including an impedance amplitude component and an impedance phase component, the NFC chip in communication with the microcontroller, the microcontroller configured to compare the impedance amplitude component and the impedance phase component to a baseline impedance amplitude and a baseline impedance phase to determine whether an object is present on the charging surface.

A wireless power transmitter system, comprising:

• a microcontroller;
• a charging surface;
• a charging source coil in communication with the microcontroller and configured to generate a first magnetic field inductively transmitting power to a charge receiving coil;
• a near-field communication (NFC) coil configured to generate a second magnetic field for transmitting information to a remote NFC coil;
• and
• an NFC chip in communication with the NFC coil and the microcontroller, the NFC chip configured to determine a vector impedance of the NFC coil, the determined vector impedance including an impedance amplitude component and an impedance phase component.