An augmented reality system including a source and a contact lens display can be used to project information from the contact lens display onto the retina of the wearer's eye. The source provides energy to the contact lens display and operates at a source frequency. The source includes a source circuit including a conductive coil. The contact lens display includes a resonant circuit including another conductive coil and a capacitive circuit. The resonant circuit receives energy from the conductive coil of the source via a magnetic field inductively coupling the conductive coils. The contact lens display additionally includes a feedback circuit to adjust the capacitance of the capacitive circuit to control a resonant frequency of the resonant circuit. The feedback circuit can control the capacitive circuit to maintain the resonant frequency of the resonant circuit near the source frequency as the wearer's eye blinks.

A power line communication device including a current path provided between a first terminal and a second terminal. A coupling circuit includes a first circuit of a first inductor connected in parallel with a first capacitor and a first resistor, wherein the coupling circuit is connected between the first and second terminals. A sensor is configured to sense a communication parameter of the coupling circuit. The communication parameter may be a resonance of the first circuit, the quality (Q) factor of the resonance, the bandwidth (BW) of the coupling circuit, the resistance of the first resistor, or the impedance of the first circuit. A transceiver is adapted to couple to the first and second terminal to transmit a signal onto the current path or receive a signal from the current path responsive to the parameter of the coupling circuit and a level of current in the current path sensed by the sensor.

A resonant magnetic coupling wireless power transfer system with calibration capabilities of the resonant frequencies of its power transmitter(s) and power receiver(s) is disclosed. The system detects the peak voltages of the coil inductors or the resonant capacitors and tunes the resonant capacitors until the detected peak voltages reach their maximal values given proper setup conditions, so as to calibrate the inductor-capacitor (LC) resonance frequencies of the power transmitter(s) and the power receiver(s) in the resonant magnetic coupling wireless power transfer system to achieve the highest power transferred to the load and a high PTE.

A resonant magnetic coupling wireless power transfer system with calibration capabilities of the resonant frequencies of its power transmitter(s) and power receiver(s) is disclosed. The system detects the peak voltages of the coil inductors or the resonant capacitors and tunes the resonant capacitors until the detected peak voltages reach their maximal values given proper setup conditions, so as to calibrate the inductor-capacitor (LC) resonance frequencies of the power transmitter(s) and the power receiver(s) in the resonant magnetic coupling wireless power transfer system to achieve the highest power transferred to the load and a high PTE.

A power line communication device including a current path provided between a first terminal and a second terminal. A coupling circuit connected between the first and second terminals includes a first circuit of a first inductor connected in parallel with a first capacitor and a first resistor. A sensor is configured to sense a communication parameter of the coupling circuit. The communication parameter may be a resonance of the first circuit, the quality (Q) factor of the resonance, the bandwidth (BW) of the coupling circuit, the resistance of the first resistor, or the impedance of the first circuit. A transceiver is adapted to couple to the first and second terminal to transmit a signal onto the current path or receive a signal from the current path responsive to the parameter of the coupling circuit and a level of current in the current path sensed by the sensor.

A local coil matrix for a magnetic resonance tomograph and a magnetic resonance tomograph with a local coil matrix are provided. The local coil matrix has a first coil with two detachable coil segments. The two coil segments have electrical connecting elements. The electrical connecting elements are configured to produce an electrical connection between the coil segments in different relative positions of the two coil segments to each other.

A power line communication device including a current path provided between a first terminal and a second terminal. A coupling circuit connected between the first and second terminals includes a first circuit of a first inductor connected in parallel with a first capacitor and a first resistor. A sensor is configured to sense a communication parameter of the coupling circuit. The communication parameter may be a resonance of the first circuit, the quality (Q) factor of the resonance, the bandwidth (BW) of the coupling circuit, the resistance of the first resistor, or the impedance of the first circuit. A transceiver is adapted to couple to the first and second terminal to transmit a signal onto the current path or receive a signal from the current path responsive to the parameter of the coupling circuit and a level of current in the current path sensed by the sensor.

A magnetic resonance coupling (MRC) wireless charging device based on a differential structure is provided. The device includes a magnetic resonance transmitter module and a magnetic resonance receiver module communicatively connected to the magnetic resonance transmitter module, where the magnetic resonance transmitter module includes a differential amplifier circuit, a plurality of transmitter-side differential filter circuits, a transmitter-side differential matching circuit and a transmitter coil that are sequentially and communicatively connected; the magnetic resonance receiver module includes a receiver coil, a receiver-side differential matching circuit, a plurality of receiver-side differential filter circuits and a current-doubler rectifier circuit that are sequentially and communicatively connected; and the transmitter coil is communicatively connected to the receiver coil. The MRC wireless charging system based on a differential structure can effectively reduce the overall electromagnetic interference and has a low working voltage and low requirements on withstanding voltages and powers of the devices.

A magnetic resonance coupling (MRC) wireless charging device based on a differential structure is provided. The device includes a magnetic resonance transmitter module and a magnetic resonance receiver module communicatively connected to the magnetic resonance transmitter module, where the magnetic resonance transmitter module includes a differential amplifier circuit, a plurality of transmitter-side differential filter circuits, a transmitter-side differential matching circuit and a transmitter coil that are sequentially and communicatively connected; the magnetic resonance receiver module includes a receiver coil, a receiver-side differential matching circuit, a plurality of receiver-side differential filter circuits and a current-doubler rectifier circuit that are sequentially and communicatively connected; and the transmitter coil is communicatively connected to the receiver coil. The MRC wireless charging system based on a differential structure can effectively reduce the overall electromagnetic interference and has a low working voltage and low requirements on withstanding voltages and powers of the devices.