Methods and apparatus for detecting the presence of undesirable foreign matter in a region between a wireless power transmission apparatus and a power reception apparatus are described. First and second detection methods, based on different detection schemes, may be used to detect and distinguish the presence of foreign matter from misalignment during power transfer operation. A first detection method may be used before power is transferred to a load in a power reception apparatus, and a second detection method may be used while power is supplied to the load.

Described herein are technologies related to an implementation of a system to measure and compensate non-linearity (e.g., echo cancellation) in a transceiver circuitry of a device. Particularly, the echo cancellation utilizes reduced number of components for power savings, and further increases efficiency of signal or data packet transmissions in the device. An echo signal is determined by sampling a power amplifier output signal. The output signal is split into signals with different delays. Down conversion and digital interpolation of the signal with the shortest delay is performed. An echo cancellation signal is calculated based on the output signal as received as an input signal to a receive chain. The calculated signal is subtracted from a received echo signal to generate an echo free signal.

Near-field power transfer systems can include antenna elements that constructed or printed close to each other in a meandered arrangement, where neighboring antenna elements conduct currents that flow in opposite directions. This current flow entirely or almost entirely cancels out any far field RF radiation generated by the antennas or otherwise generated by the electromagnetic effects of the current flow. For a first current flowing in a first path, there may be a second current flowing in a second cancellation path, which cancels the far field radiation produced by the first current flowing in the first path. Therefore, there may be no radiation of power to the far field. Such cancellation, may not occur in a near-field active zone, where the transfer of power may occur between the transmitter and the receiver. A ground plane may block the leakage of power from the back of a transmitter and/or a receiver.

A method is provided introducing a phase offset between signals applied to antenna ports of an antenna having multiple antenna elements, such that a first signal applied to one of the antenna ports operatively coupled to one of the antenna elements has a different phase than a second signal applied to another one of antenna ports operatively coupled to another one of the antenna elements to obtain an antenna pattern control. A reduced power is used that is lower than the power used in a non-pattern control operation of the antenna such that a wireless link performance criteria is met with equipment at a far-field point using the reduced power compared to the non-pattern control operation, thereby reducing near field radiation.

Aspects of the present disclosure are directed to circuits, apparatuses and methods for communicating data between capacitive-isolated devices. According to an example embodiment, an apparatus includes a transmitter circuit configured to transmit a first single-ended data signal over a first signal path. The apparatus also includes a receiver circuit. The receiver circuit includes a differential amplifier having a first input coupled to receive a second single-ended signal from a second signal path of the plurality of signal paths and includes a second input coupled to receive a reference signal from a third signal path of the plurality of signal paths. The differential amplifier outputs a third single-ended signal indicative of a voltage difference between the first and second inputs. The receiver circuit also includes a common mode suppression circuit configured to remove a common mode voltage from the first and second inputs of the differential amplifier.

A system comprises an inverter configured to convert DC power from a battery to AC power to drive a motor, wherein the inverter includes: a galvanic isolator separating a high voltage area from a low voltage area; a low voltage phase controller in the low voltage area, the low voltage phase controller configured to receive a pulse width modulation (PWM) signal from an inverter controller and adjust the received PWM signal based on a feedback signal; and a high voltage phase controller in the high voltage area, the high voltage phase controller configured to receive the adjusted PWM signal from the low voltage phase controller, provide the adjusted PWM signal to a phase switch, and provide the feedback signal based on an on-time measurement of the phase switch.

In an interface unit, a shield layer includes an aperture through which magnetic flux generated by a power feeding coil of an antenna passes. Since the antenna is smaller than the shield layer, the aperture is much smaller than the shield layer. Thus, noise constituted by electromagnetic waves that travel from inside to outside of a computer via an aperture provided in an upper surface cover is blocked. During communication, the antenna and the shield layer are electromagnetically coupled to each other, and the shield layer defines and functions as an antenna. This allows proper communication with a communication target.

In a first aspect of the present invention, a wireless power transmission link is proposed, which while substantially maintaining resonant coupling condition (resonance frequency of the source resonant circuit is substantially equal to the resonance frequency of the load resonant circuit) detects a coupling condition of the wireless power transmission link.

In a further aspect of the present invention, a wireless power transmission link is suggested, which while substantially maintaining resonant coupling condition (resonance frequency of the source resonant circuit is substantially equal to the resonance frequency of the load resonance circuit) controlling the operating state of the wireless power transmission link such, that the coupling condition of wireless power transmission link is substantially limited to the critical coupling condition.

Techniques for duplex communication and power transfer across an isolator are provided. In an example, a first transceiver coupled to a firs-t side of an isolator can include a transmit modulator configured to receive first data and timing signals, to provide control signals to oscillate an output of the transceiver to transmit power and to order each half-cycle of an oscillation cycle of the output to transmit the first data. A second transceiver coupled to a second side of the isolator can include a receive detection circuit configured to compare a received oscillation cycle with a plurality of thresholds and to provide a plurality of comparator outputs indicative of reception of the positive half-cycle and the negative half-cycle, and a receive decoder configured to identify the order of half-cycles and to provide an output indicative of logic level of the first data.

A method for transmitting electric power and signals between a wall and a leaf pivotally mounted on the wall. The method includes transmitting the electric power so as to be galvanically isolated, and transmitting the signals optically or optoelectronically.