Abstract:
In certain aspects, a variable capacitor comprises a well having a first side and a second side, an N+ diffusion abutted the well at the first side, a P+ diffusion abutted the well at the second side, and an insulator on the well. The variable capacitor further comprises a gate plate on the insulator having a first gate segment and a second gate segment, wherein the first gate segment and the second gate segment are configured to have different work functions.
Abstract:
Certain aspects of the present disclosure provide a variable capacitor. The variable capacitor generally includes a semiconductor region, a dielectric layer disposed adjacent to the semiconductor region, and a first non-insulative region disposed above the dielectric layer, and a second non-insulative region disposed adjacent to the semiconductor region. In certain aspects, a doping concentration of the semiconductor region changes as a function of a distance across the semiconductor region from the dielectric layer or the second non-insulative region.
Abstract:
The present disclosure provides a semiconductor capacitor. The semiconductor capacitor generally includes a first non-insulative region disposed above an insulative layer, an insulative region, and a second non-insulative region disposed adjacent to the insulative region, wherein the insulative layer is disposed above the second non-insulative region and the insulative region. At least a portion of the insulative region is disposed above one or more portions of the second non-insulative region.
Abstract:
A tunable capacitor may include a first terminal having a first semiconductor component with a first polarity. The tunable capacitor may also include a second terminal having a second semiconductor component with a second polarity. The second component may be adjacent to the first semiconductor component. The tunable capacitor may further include a first conductive material electrically coupled to a first depletion region at a first sidewall of the first semiconductor component.
Abstract:
Techniques for controlling a resonant network are disclosed. An example of an apparatus for varying capacitance in a resonant network includes a variable capacitor circuit configured to vary a capacitance in response to a control signal, at least one biasing component operably coupled to the variable capacitor circuit, and a control circuit configured to generate the control signal, such that the control signal includes a first tuning value corresponding to a first capacitance value, and output the control signal at the first tuning value to reduce an impedance of the at least one biasing component and vary the capacitance of the variable capacitor circuit, such that the impedance of the at least one biasing component subsequently increases when the first capacitance value is realized.
Abstract:
Methods and circuitry are disclosed to produce a first signal representative of the AC voltage signal and a second signal representative of an AC current signal. The first and second signals may be combined with a clock signal to produce a third signal. A phase angle between the AC voltage signal and the AC current signal may be determined based on a pulse count indicative of how many pulses occur in the third signal over a predetermined period of time.
Abstract:
An apparatus for receiving wireless power is provided. The apparatus comprises a coupler configured to receive a first amount of wireless power via a wireless field generated by a wireless power transmitter. The apparatus comprises a sensor circuit configured to measure the first amount of wireless power. The apparatus comprises a controller configured to instruct a feedback circuit to provide an indication to a user based on a comparison of the first amount of wireless power measured by the sensor circuit to a power threshold.
Abstract:
An apparatus and method for lost power detection are described. In one implementation, an apparatus for wirelessly transferring power includes an antenna configured to provide wireless power to a chargeable device sufficient to charge or power the chargeable device positioned within a charging region of the antenna. The apparatus further includes a receiver configured to receive from the chargeable device a measurement of a first amount of energy received by the chargeable device over a first period of time. The apparatus further includes a processor configured to measure a second amount of energy provided by the antenna over a second period of time, compare the first amount of energy to the second amount of energy, and determine whether another object is absorbing power provided via the antenna based at least in part on comparing the first amount and the second amount of energy.
Abstract:
A uniform magnetic field may provide better performance in wireless power transmitters due to smaller impedance variations in an output of a power amplifier of a wireless power transmitter and also allow for wireless power transmitter pads to be thinner. One aspect of the disclosure provides a device for wireless power transfer. The device comprises a substantially planar transmit antenna that is configured to generate a magnetic field. The device also comprises a pad having a charging surface. At least a portion of the transmit antenna is disposed in the pad. The device also comprises a ferromagnetic material having a shape and a position relative to the transmit antenna. At least one of the shape or position of the ferromagnetic material, or a combination thereof, is selected to modify a distribution of the magnetic field at the charging surface.
Abstract:
A method and system for providing wireless power transfer through a metal object is provided. In one aspect, an apparatus for wirelessly receiving power via a magnetic field is provided. The apparatus includes a metal cover including an inner portion and an outer portion. The outer portion is configured to form a loop around the inner portion of the metal cover. The outer portion is configured to inductively couple power via the magnetic field. The apparatus includes a receive circuit electrically coupled to the outer portion and configured to receive a current from the outer portion generated in response to the magnetic field. The receive circuit is configured to charge or power a load based on the current.