Abstract: This disclosure provides systems, methods and apparatus for wireless power transfer. In one aspect an apparatus for wirelessly transferring power from a charging power source to a device is provided. The apparatus includes a first strand wound in one or more turns and operationally coupled to the charging power source and a second strand wound together with the first strand in one or more turns and operationally coupled to the charging power source. The apparatus further includes an inductor circuit connected to the first strand and disconnected from the second strand. The inductor circuit is further configured to reduce a current difference between a first current flowing through the first strand and a second current flowing through the second strand.

Abstract: This disclosure provides systems, methods and apparatus for detecting foreign objects. In one aspect an apparatus for detecting a presence of an object in a magnetic field is provided. The apparatus includes a power circuit configured to generate the magnetic field and transfer power wirelessly at a level sufficient to power or charge a load via the magnetic field. The apparatus further includes a detection circuit configured to transmit signals and detect, based on a reflection of the transmitted signals, a frequency of vibration of the object caused by the magnetic field.

Abstract: This disclosure provides systems, methods and apparatus for detecting foreign objects. In one aspect an apparatus for detecting a presence of an object is provided. The apparatus includes a resonant circuit having a resonant frequency. The resonant circuit includes a sense circuit including an electrically conductive structure. The apparatus further includes a coupling circuit coupled to the sense circuit. The apparatus further includes a detection circuit coupled to the sense circuit via the coupling circuit. The detection circuit is configured to detect the presence of the object in response to detecting a difference between a measured characteristic that depends on a frequency at which the resonant circuit is resonating and a corresponding characteristic that depends on the resonant frequency of the resonant circuit. The coupling circuit is configured to reduce a variation of the resonant frequency by the detection circuit in the absence of the object.

Abstract: Exemplary embodiments are directed to wireless power transfer. A wireless power transmitter includes a transmit antenna configured as a resonant tank including a loop inductor and an antenna capacitance. The transmitter further includes an amplifier configured to drive the transmit antenna and a matching circuit operably coupled between the transmit antenna and the amplifier. The transmitter also includes a capacitor integrating the antenna capacitance and a matching circuit capacitance.

Abstract: A wireless power system includes a power source, power receiver, and components thereof. The system can also include a parasitic antenna that can improve the coupling to the power source in various modes. The antenna can have both a variable capacitor and a variable inductor, and both of those can be changed in order to change characteristics of the matching.

Abstract: Exemplary embodiments are directed to wireless charging. An electronic device may comprise at least one receive antenna integrated within an electronic device and configured to receive wireless power from a wireless transmit antenna. Further, the at least one receive antenna may be spaced from each conductive component within the electronic device having a clearance therebetween adapted to enable formation of a magnetic field around the loop conductor.

Abstract: Improved battery-charging system for a vehicle. Primary and secondary coils are located in places where the vehicle can receive power from the primary coil by pulling into a parking space, for example. The parking space may have a coil embedded in the ground, or may have an array of coils embedded in the ground. A guidance system is disclosed. Fine positioning is also disclosed. The secondary coil in the vehicle can also be raised or lowered to improve coupling.

Abstract: A wireless power transmission system and method for transmitting power from a charging base to receivers located both on and outside the charging base. The system utilizes wireless power transmission of a transmitter with a wound transmit coil.

Abstract: Exemplary embodiments are directed to wireless power transfer. A wireless power transmitter includes a transmit antenna configured as a resonant tank including a loop inductor and an antenna capacitance. The transmitter further includes an amplifier configured to drive the transmit antenna and a matching circuit operably coupled between the transmit antenna and the amplifier. The transmitter also includes a capacitor integrating the antenna capacitance and a matching circuit capacitance.

Abstract: Exemplary embodiments are directed to wireless power transfer. A wireless power receiver includes a receive antenna for coupling with a transmit antenna of transmitter generating a magnetic near field. The receive antenna receives wireless power from the magnetic near field and includes a resonant tank and a parasitic resonant tank wirelessly coupled to the resonant tank. A wireless power transmitter includes a transmit antenna for coupling with a receive antenna of a receiver. The transmit antenna generates a magnetic near field for transmission of wireless power and includes a resonant tank and a parasitic resonant tank coupled to the resonant tank.

Abstract: A wireless powering and charging system is described. The antennas can be high q loop antennas. The antennas can use coupling between a first part and a second part.

Abstract: Improved battery-charging system for a vehicle. Primary and secondary coils are located in places where the vehicle can receive power from the primary coil by pulling into a parking space, for example. The parking space may have a coil embedded in the ground, or may have an array of coils embedded in the ground. A guidance system is disclosed. Fine positioning is also disclosed. The secondary coil in the vehicle can also be raised or lowered to improve coupling.

Abstract: Exemplary embodiments are directed to wireless power transfer. A wireless power transmission receiver includes a receive antenna including a parallel resonator configured to resonate in response to a magnetic near-field and couple wireless power therefrom. The receiver further includes a passive rectifier circuit coupled to the parallel resonator. The passive rectifier circuit is configured to transform a load impedance to the parallel resonator.

Abstract: A wireless power system includes a power source, power receiver, and components thereof. A current sensor senses the amount of current through the antenna. That amount of current is then used to adjust characteristics of the transmitting or receiving.

Abstract: Techniques for wireless power transmission. An antenna has a part that amplifies a flux to make the antenna have a larger effective size than its actual size.

Abstract: Magneto mechanical systems used for wireless power reception. A miniature moving magnet is placed in an oscillating magnetic field. Movement of the magnet causes power to be generated.

Abstract: Optimizing a wireless power system by separately optimizing received power and efficiency. Either one or both of received power and/or efficiency can be optimized in a way that maintains the values to maximize transferred power.

Abstract: A base including a magnetically resonant antenna therein for relaying energy to a portable device.

Abstract: Exemplary embodiments are directed to wireless power transfer. A wireless power receiver includes a receive antenna for coupling with a transmit antenna of transmitter generating a magnetic near field. The receive antenna receives wireless power from the magnetic near field and includes a resonant tank and a parasitic resonant tank wirelessly coupled to the resonant tank. A wireless power transmitter includes a transmit antenna for coupling with a receive antenna of a receiver. The transmit antenna generates a magnetic near field for transmission of wireless power and includes a resonant tank and a parasitic resonant tank coupled to the resonant tank.

Abstract: Embodiments are directed to a wireless power antenna alignment systems and methods for electric vehicles. A system may include a sensor configured to detect the strength of an electromagnetic field in multiple dimensions and a processor configured to determine at least one of a direction and a position of a transmitted beacon signal based on an output of the sensor.