A magnetic field is formed at a predetermined region. A magnetic field formation device configured to generate a variable magnetic field at a predetermined region includes power supplying resonators. All of the power supplying resonators are provided so that coil surfaces oppose the predetermined region, and at least one of the power supplying resonators is provided to have a coil surface direction intersecting with the coil surface direction of the other one of the power supplying resonators.

Methods and systems for charging a device. The method may involve providing a first housing and a second housing, wherein each housing is configured with a first coil, a second coil, and control logic to control the functioning of their respective first and second coils depending on the orientations of the housings. The method may further involve physically linking the first housing and the second housing via a first flexible connection.

A two-stage wireless power transfer system has three distinct components. A first component has a first-stage wireless power transmitter (TX). A second component has a first-stage wireless power receiver (RX) hardwired to a second-stage wireless power transmitter. A third component, which may be a rechargeable, battery-powered device like a cell phone, has a second-stage wireless power receiver. The first stage has TX and RX inductor coils that are substantially larger than the TX and RX coils of the second stage. A Z-gap between the first and second components can be relatively large, while still achieving relatively high overall power transfer efficiency as long as the Z-gap between the second and third components is relatively small.

A method of transmitting power wirelessly from at least two transmitter loops to at least one power receiver. The method comprises separately supplying a respective alternating current to each one of the transmitter loops thereby to transmit wireless power for receipt by the at least one power receiver. Also provided is a method of receiving power wirelessly. Associated apparatuses and an associated system are also provided.

A wireless power transmission system includes: a wireless power transmission apparatus including: a transmission coil configured to form mutual coupling with an auxiliary coil disposed outside of a living body; and a controller configured to control a supply of power by a power source to the transmission coil to wirelessly transmit the power from the transmission coil, using the auxiliary coil, to a wireless power reception apparatus disposed inside the living body through the mutual coupling, wherein a distance between the transmission coil and the auxiliary coil is adjustable.

A wireless power transmission system includes: a wireless power transmission apparatus including: a transmission coil configured to form mutual coupling with an auxiliary coil disposed outside of a living body; and a controller configured to control a supply of power by a power source to the transmission coil to wirelessly transmit the power from the transmission coil, using the auxiliary coil, to a wireless power reception apparatus disposed inside the living body through the mutual coupling, wherein a distance between the transmission coil and the auxiliary coil is adjustable.

Described herein are improved configurations for a wireless power transfer. The parameters of components of the wireless energy transfer system are adjusted to control the power delivered to the load at the device. The power output of the source amplifier is controlled to maintain a substantially 50% duty cycle at the rectifier of the device.

A radiofrequency-powered device such as a wireless passive sensor node, for instance, comprises a radiofrequency energy harvesting circuit configured to be coupled to an antenna to harvest radiofrequency energy captured by the antenna from a radiofrequency signal. The radiofrequency energy harvesting circuit is configured to be coupled to an energy storage component to store therein energy harvested via the radiofrequency energy harvesting circuit. The device comprises user circuitry configured to be supplied with energy harvested via the radiofrequency energy harvesting circuit and to operate in accordance with one of a plurality of configurations as a function of configuration data supplied thereto. A receiver circuit coupled to the radiofrequency energy harvesting circuit is configured to receive a configuration data signal modulating the radiofrequency signal and supply to the user circuitry configuration data extracted from the configuration data signal received.

A relay apparatus in a wireless power transmission system includes a relay power reception antenna that receives power transmission alternating current power from a power transmission power transmission antenna, a relay rectifier that converts the power transmission alternating current power into relay direct current power, a relay inverter circuit that converts the relay direct current power into relay alternating current power, and a relay power transmission antenna that wirelessly transmits the relay alternating current power. When transmitting data to the power transmission apparatus through amplitude modulation, the relay apparatus varies amplitude of voltage of the power transmission alternating current power received by the relay power reception antenna between a first amplitude and a second amplitude and performs control for eliminating a difference between a third amplitude of the relay alternating current power and a fourth amplitude of the relay alternating current power.

A relay apparatus in a wireless power transmission system includes a relay power reception antenna that receives power transmission alternating current power from a power transmission power transmission antenna, a relay rectifier that converts the power transmission alternating current power into relay direct current power, a relay inverter circuit that converts the relay direct current power into relay alternating current power, and a relay power transmission antenna that wirelessly transmits the relay alternating current power. When transmitting data to the power transmission apparatus through amplitude modulation, the relay apparatus varies amplitude of voltage of the power transmission alternating current power received by the relay power reception antenna between a first amplitude and a second amplitude and performs control for eliminating a difference between a third amplitude of the relay alternating current power and a fourth amplitude of the relay alternating current power.