Abstract: An electronic device may be provided with wireless communications circuitry and control circuitry. The wireless communications circuitry may include centimeter and millimeter wave transceiver circuitry and a phased antenna array. A dielectric cover may be formed over the phased antenna array. The phased antenna array may transmit and receive antenna signals through the dielectric cover. The dielectric cover may have first and second opposing surfaces. The second surface may face the phased antenna array and may have a curvature. The antenna elements of the phased antenna array may be formed on a dielectric substrate. The dielectric substrate may have one or more thinned regions between antenna elements of the phased antenna array to promote bending. The dielectric substrate may have a smaller thickness in the thinned region than in the regions under the antenna elements. The dielectric substrate may be totally removed in the thinned region.

Abstract: A wireless power transmission system has a wireless power receiving device that is configured to receive power from a wireless power transmitting device. The power transmitting device may have a conductive housing portion at a front face and a reflector at a rear face that form a cavity for an antenna that is configured to transmit wireless charging signals to the power receiving device. The power transmitting device may be a desktop computer. The power receiving device may include an antenna that receives signals from the power transmitting device and rectifier circuitry that converts signals from the antenna to corresponding rectified direct current voltage signals that may be used to charge a battery in the power receiving device. The antenna may include a cavity formed from a conductive housing for the power receiving device. The power receiving device may be an accessory such as a keyboard, trackpad, or computer mouse.

Abstract: An electronic device may include a peripheral conductive housing wall. The housing wall may be patterned to form first and second continuous regions defining opposing edges of a patterned region. The patterned region may include slots that divide the wall into conductive structures between the first and second continuous regions. A tuning element for an antenna in the device may be formed from the conductive structures and the slots in the patterned region. The slots and the conductive structures in the patterned region may be configured to mitigate any excessive capacitances between the first and second continuous regions in one or more desired frequency bands to optimize antenna efficiency. The slots may be narrow enough so as to be invisible to the un-aided human eye. This may configure the first and second continuous regions to appear to a user as a single continuous piece of conductor.

Abstract: Methods and devices useful in radio frequency (RF) signal transmission are provided. By way of example, a wireless electronic device may include a transceiver, and an enclosure in which the transceiver is disposed. The enclosure may include an RF transparent layer and an RF opaque coating disposed on the RF transparent layer, where the RF opaque coating includes a pattern formed therein to enable RF signals to pass therethrough.

Abstract: An electronic device may include a peripheral conductive housing wall. The housing wall may be patterned to form first and second continuous regions defining opposing edges of a patterned region. The patterned region may include slots that divide the wall into conductive structures between the first and second continuous regions. A tuning element for an antenna in the device may be formed from the conductive structures and the slots in the patterned region. The slots and the conductive structures in the patterned region may be configured to mitigate any excessive capacitances between the first and second continuous regions in one or more desired frequency bands to optimize antenna efficiency. The slots may be narrow enough so as to be invisible to the un-aided human eye. This may configure the first and second continuous regions to appear to a user as a single continuous piece of conductor.

Abstract: An electronic device may be provided with wireless communications circuitry and control circuitry. The wireless communications circuitry may include millimeter wave transceiver circuitry and a phased antenna array. The phased antenna array may transmit and receive millimeter wave signals. Beam steering circuitry may be coupled to the phased antenna array and may be adjusted to steer the millimeter wave signals in a particular direction. The control circuitry may track the location of an external device using sensor data. The control circuitry may control a mechanical positioner to mechanically adjust an orientation of the phased antenna array and/or may control the beam steering circuitry to steer the millimeter wave signals towards the location of the external device. In this way, a line of sight millimeter wave communications link may be maintained between the phased antenna array and the external device even if the external device moves over time.

Abstract: An electronic device may be provided with wireless communications circuitry and control circuitry. The wireless communications circuitry may include millimeter wave transceiver circuitry and a phased antenna array. The phased antenna array may transmit and receive millimeter wave signals. Beam steering circuitry may be coupled to the phased antenna array and may be adjusted to steer the millimeter wave signals in a particular direction. The control circuitry may track the location of an external device using sensor data. The control circuitry may control a mechanical positioner to mechanically adjust an orientation of the phased antenna array and/or may control the beam steering circuitry to steer the millimeter wave signals towards the location of the external device. In this way, a line of sight millimeter wave communications link may be maintained between the phased antenna array and the external device even if the external device moves over time.

Abstract: An electronic device may have a housing and other structures that form an antenna ground for an antenna. An antenna resonating element arm for the antenna may extend along the periphery of the housing. The resonating element arm may have opposing first and second ends. A return path may couple the resonating element arm to the antenna ground at the first end. An antenna feed may be coupled between the resonating element arm and the antenna ground in parallel with the return path. Electrical components such as first and second capacitors may be coupled between the antenna resonating element arm and the antenna ground. A first of the capacitors may be coupled between the antenna resonating element arm and the antenna ground at a location between the first and second ends. A second of the capacitors may be coupled between the second end and the antenna ground.

Abstract: An electronic device may include a substrate and a conductive layer on the substrate. The conductive layer may be patterned to form a first region and a second region that surrounds and defines the shape of the first region. The first region may be formed from a continuous portion of the conductive layer. The second region may include a grid of openings that divides the conductive layer into an array of patches. The first region may form an antenna resonating element for an antenna. The second region may block antenna currents from the antenna resonating element and may be transparent to radio-frequency electromagnetic waves. The openings may have a width that is too narrow to be discerned by the human eye. This may configure the first and second regions to appear as a single continuous conductive layer despite the fact that an antenna resonating element is formed therein.

Abstract: An electronic device may communicate with an external device and may include one or more phased antenna arrays that transmit and receive a beam of millimeter wave signals. Beam steering circuitry may be coupled to the phased antenna array and may be adjusted to steer a direction of the beam. Control circuitry may control the beam steering circuitry to sweep the beam of millimeter wave signals over multiple beam directions. The control circuitry may gather wireless performance data and may compare the wireless performance metric data at each beam direction in the sweep prior to gathering wireless performance metric data at other beam directions in the sweep. The first beam direction in the sweep may be selected based on an initial position of the external device and/or based on sensor data gathered by the control circuitry.

Abstract: Methods and devices useful in radio frequency (RF) signal transmission are provided. By way of example, a wireless electronic device may include a transceiver, and an enclosure in which the transceiver is disposed. The enclosure may include an RF transparent layer and an RF opaque coating disposed on the RF transparent layer, where the RF opaque coating includes a pattern formed therein to enable RF signals to pass therethrough.

Abstract: An electronic device may have a display cover layer mounted to a metal housing. Electrical component layers such as a display layer, touch sensor layer, and near-field communications antenna layer may be mounted under the display cover layer. An antenna feed may have a positive feed terminal coupled to the electrical component layers and a ground feed terminal coupled to the metal housing. The electrical component layers may serve as an antenna resonating element for an antenna. The antenna may cover cellular telephone bands and may receive satellite navigation system signals. A system-in-package device may be mounted to the metal housing. A flexible printed circuit may extend between the electrical component layers and the system-in-package device. A mounting bracket for the system-in-package device may be provided with electrical isolation to enhance antenna performance in bands such as a satellite navigation system band.

Abstract: An electronic device may have a housing and other structures that form an antenna ground for an antenna. An antenna resonating element arm for the antenna may extend along the periphery of the housing. The resonating element arm may have opposing first and second ends. A return path may couple the resonating element arm to the antenna ground at the first end. An antenna feed may be coupled between the resonating element arm and the antenna ground in parallel with the return path. Electrical components such as first and second capacitors may be coupled between the antenna resonating element arm and the antenna ground. A first of the capacitors may be coupled between the antenna resonating element arm and the antenna ground at a location between the first and second ends. A second of the capacitors may be coupled between the second end and the antenna ground.

Abstract: In some aspects, the disclosure is directed to methods and systems of a multi-input receiver. In one or more embodiments, a receiver receives a plurality of signals each via a respective one of a plurality of wireless channels. In one or more embodiments, a processing stage of the receiver combines the received plurality of signals into a combined signal for input to an analog-to-digital converter (ADC) of the receiver. In one or more embodiments, the ADC generates, at a predetermined sampling frequency, samples of the combined signal. In one or more embodiments, the receiver recovers from the generated samples at least one signal component corresponding to at least one of the plurality of signals.

Abstract: A fracture interrogation system includes an antenna adapted for placement in a subterranean wellbore and a plurality of pseudoparticles adapted for distribution with a proppant material into hydraulic fractures along the wellbore. The presence of the pseudoparticles in the hydraulic fractures is detectable by the antenna. The pseudoparticles can include a magnetoelastic resonator having a resonant frequency. An interrogation field excites the resonators at the resonant frequency for detection by the antenna. The same or a different antenna can act as the interrogation field source, and the system can be configured to operate in a talk-and-listen mode to better separate the response signal from the interrogation signal. Electromagnetic, mechanical, or acoustic impulses can be used to excite resonators of the pseudoparticles.

Abstract: Methods, systems, and apparatuses, including electrical circuits, are described for spread spectrum ADC noise reduction. An analog-to-digital converter may include an analog modulator to modulate an input analog signal according to a pseudo-noise sequence. An ADC core may convert the modulated analog input signal to a digital signal representation thereof. The digital signal may be demodulated using the pseudo-noise sequence to generate a noise-spread signal with reduced noise spectral density. The analog modulator and digital demodulator may also be configured in an analog-to-digital converter that includes a comparator and successive approximation register (SAR) logic, rather than an ADC core, in a SAR implementation. Multi-lane, interleaved analog-to-digital conversion circuits are also described using the inventive techniques. Analog-to-digital converters including DC offset components and methods performed according to the inventive techniques are also described.

Abstract: In some aspects, the disclosure is directed to methods and systems of a multi-input receiver. In one or more embodiments, a receiver receives a plurality of signals each via a respective one of a plurality of wireless channels. In one or more embodiments, a processing stage of the receiver combines the received plurality of signals into a combined signal for input to an analog-to-digital converter (ADC) of the receiver. In one or more embodiments, the ADC generates, at a predetermined sampling frequency, samples of the combined signal. In one or more embodiments, the receiver recovers from the generated samples at least one signal component corresponding to at least one of the plurality of signals.

Abstract: Methods, systems, and apparatuses, including electrical circuits, are described for spread spectrum ADC noise reduction. An analog-to-digital converter may include an analog modulator to modulate an input analog signal according to a pseudo-noise sequence. An ADC core may convert the modulated analog input signal to a digital signal representation thereof. The digital signal may be demodulated using the pseudo-noise sequence to generate a noise-spread signal with reduced noise spectral density. The analog modulator and digital demodulator may also be configured in an analog-to-digital converter that includes a comparator and successive approximation register (SAR) logic, rather than an ADC core, in a SAR implementation. Multi-lane, interleaved analog-to-digital conversion circuits are also described using the inventive techniques. Analog-to-digital converters including DC offset components and methods performed according to the inventive techniques are also described.

Abstract: An Analog to Digital Converter (ADC) includes an ADC core, a first switched capacitor voltage regulator, and a second switched capacitor voltage regulator. The ADC core includes a plurality of digital components that sample an incoming signal based on an ADC clock, a first voltage, and a first ground and a plurality of analog components configured to operate using a second voltage and a second ground. The first switched capacitor voltage regulator produces the first voltage and the first ground for the plurality of digital components using a supply voltage, a supply ground, and the ADC clock. The second switched capacitor voltage regulator produces the second voltage and the second ground using the supply voltage, the supply ground, and the ADC clock. Switching of the first and second switched capacitor voltage regulators is performed using complementary and non-overlapping clocks having switching frequency that is based upon the ADC clock.

Abstract: An analog-to-digital converter (ADC) utilizing a capacitor array during multiple conversion stages and amplifier sharing across multiple lanes. In various embodiments, the ADC includes N lanes, each of the lanes including a capacitor array. A plurality of switches coupled to each capacitor array selectively redistributes a sampled charge during N clock phases corresponding to N conversion stages, the conversion stages including a sampling stage performed on an analog input signal, at least one quantization stage, and N?2 multiplying digital-to-analog conversion (MDAC) stages for generating residue voltages. The MDAC stages utilize a plurality of N?2 amplifiers shared by the N lanes. In operation, each amplifier may be used in an interleaved manner to support, during a given clock phase, an MDAC stage of one of the lanes of the ADC. Likewise, one or more comparators of a lane may be leveraged to perform multiple quantization stages during the N clock phases.