In accordance with embodiments of the present invention, a wireless power transmitter includes a transmit coil that includes a plurality of concentric coils; a switch circuit coupled to the plurality of concentric coils; a driver coupled to provide a voltage to the switch circuit; and a controller coupled to the switch circuit, the controller providing control signals to the switch circuit selecting to provide the voltage across one or more of the plurality of concentric coils depending on a Q-factor measuring in the presence of a receive coil. A method of operating a wireless power transmitter includes determining a measured Q-factor for each of a plurality of configurations of concentric transmit coils; determining a difference between each of the measured Q-factors and a standard Q-factor; and selecting one of the plurality of configurations based on the differences.

The present invention relates to a foreign object detecting method, and a device and system therefor. A method for detecting a foreign object in a wireless power transmitter according to an embodiment of the present invention may comprise the steps of: when an object placed in a charging area is sensed, measuring quality factor values within an operating frequency band to find a measured peak frequency at which the maximum quality factor value is measured; storing the measured peak frequency and the measured quality factor value corresponding to the measured peak frequency; transmitting information on the type of transmitter to an identified wireless power receiver; receiving a reference quality factor value and a reference peak frequency corresponding to the type of transmitter; calculating a measured inductance by using the measured peak frequency; calculating a reference inductance by using the reference peak frequency; and detecting a foreign object by using at least one of the reference quality factor value, the reference peak frequency, and the reference inductance.

A solid state drive (SSD) with improved techniques for testing power loss protection (PLP) capacitors and a method for testing PLP capacitors of SSDs is disclosed. In one embodiment, the SSD includes a memory controller and one or more non-volatile memory devices and a volatile memory device coupled to the memory controller. The SSD also includes a PLP capacitor configured to supply a first voltage to the memory controller, the one or more non-volatile memory devices, and the volatile memory device in the event of a power loss or failure of the SSD. In one embodiment, the PLP capacitor is further configured to increase the first voltage to a second voltage prior to testing the PLP capacitor. In another embodiment, the memory controller is configured to reduce a volume of data stored in the volatile memory device prior to testing the PLP capacitor.

A wireless charger includes a rectifier, a first filter that includes an inductor, a resonant tank circuit, and a second filter that includes a switch. The rectifier receives a drive signal from a voltage supply and generates a rectified voltage signal. The rectified voltage signal is filtered by the first filter and the filtered signal is provided to the tank circuit, which resonates to provide power wirelessly to a receiver. The switch of the second filter is connected in parallel with the inductor of the first filter. The switch is closed in order to bypass the inductor during a detection phase in which the wireless charger determines a quality factor of the tank circuit.

In a wireless charging system, a power-transmitting node (TX) has a power transmitter for transmitting power wirelessly to a power-receiving node (RX), a sampling and sensing circuit, a processor, and a signal receiver for receiving signals from the RX. The processor detects the presence of a foreign object (FO) during a power-transfer session using Quality Factor (QF) values. Estimated QF parameters are determined via exponential curve fitting using peak values of a damped sinusoidal waveform generated by a resonant circuit. Then the estimated parameters in the exponential curve are used to calculate the QF, which provides a robust measurement result even in a noisy environment.

The invention relates to an oscillating sensor for a measurement device comprising: an oscillator comprising: a resonance circuit for providing an oscillation signal; a gain stage configured to provide a feed-back to the resonance circuit to inject energy for excitation of the oscillator to maintain oscillation; at least one calibration element to adjust the open loop gain of the oscillator; a calibration unit to provide a modulated calibration control signal to selectively adjust an electrical measure of the at least one calibration element based on at least one predetermined duty cycle, wherein the calibration unit is further configured to provide the modulated calibration control signal with at least one cycle frequency which depends on the oscillation frequency.

A system and method for determining a microwave beam and a power setting for wireless power transfer within a volume with a beamforming antenna. The method includes determining a perimeter for the volume, and determining a transmit power threshold based on the perimeter. The method includes establishing a communication link with a mobile electronic device within the volume, and determining a position of the mobile electronic device. The method includes sensing whether a person is located within the volume, and, when a person is located within the volume, sensing a position of the person, determining a microwave beam based on the position of the mobile electronic device and the position of the person, and determining a power setting for the microwave beam based on the position of the mobile electronic device, the position of the person, the transmit power threshold, and a power density distribution for the microwave beam.

A method comprises collecting a data set of field characterization measurements at a location inside a reverberant cavity excited by signals having multiple discrete electromagnetic frequencies; and performing a number (n) of circular shifts on the data set by a frequency step (f) and computing a covariance-based coefficient at each shift until the coefficient indicates a lack of correlation. The method further comprises computing a quality factor (Q) of the reverberant cavity as fc/(fn), where fc is center frequency of the data set.

A method for determining a quality factor of an electrostatically actuated oscillator, the oscillator having a resonance frequency, the method including generating an excitation voltage defined as being the sum of a sinusoidal voltage and a voltage pulse; applying the excitation voltage at the input of the oscillator; acquiring in the time domain a response voltage present at the output of the oscillator after having ceased applying the excitation voltage at the input of the oscillator; determining the quality factor of the oscillator from the response voltage acquired at the output of the oscillator.

An RF cable includes a connector housing having an RF signal output interface, a cable body having a first end portion connected to the connector housing and a second end portion comprising an RF signal input interface, an RF signal transmission path formed from the RF signal input interface through the cable body and the connector housing to the RF signal output interface, and a power measurement device integrated into the connector housing and configured to measure a power value of an RF signal transmitted through the RF signal transmission path. The RF cable further includes a measurement signal output interface, and a measurement signal transmission line connecting the power measurement device to the measurement signal output interface, the power measurement device being configured to output a measurement signal indicating the measured power value of the RF signal at the measurement signal output interface.