Abstract: An electronic device such as a wristwatch may have a housing with metal sidewalls and a display having conductive display structures. Printed circuits having corresponding ground traces may be coupled to the display for conveying data to and/or from the display. The conductive display structures may be separated from the metal sidewalls by a gap. A conductive interconnect may be coupled to the metal sidewalls and may extend across the gap to the conductive display structures. The conductive interconnect may be coupled to the ground traces on the printed circuits and/or may be shorted or capacitively coupled to the conductive display structures. When configured in this way, the metal sidewalls, the conductive display structures, and the conductive interconnect may define the edges of a slot antenna resonating element for a slot antenna.

Abstract: An electronic device such as a wristwatch may have a housing with metal portions such as metal sidewalls. The housing may form an antenna ground for an antenna. An antenna resonating element for the antenna may be formed from a stack of capacitively coupled component layers such as a display layer, touch sensor layer, and near-field communications antenna layer at a front face of the device. An additional antenna may be formed from a peripheral resonating element that runs along a peripheral edge of the device and the antenna ground. A rear face antenna may be formed using a wireless power receiving coil as a radio-frequency antenna resonating element or may be formed from metal antenna traces on a plastic support for light-based components.

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 such as a wristwatch may include a housing with a dielectric rear wall. Wireless circuitry in the device may include an antenna formed on or over the rear wall. Matching circuitry may match the impedance of the antenna to the rest of the wireless circuitry. Processing circuitry may gather receive signal strength information and/or phase and magnitude information from radio-frequency signals received through the rear wall. The processing circuitry may track the position of the device and accumulate user statistics over time. The processing circuitry may determine whether changes in loading of the antenna through the dielectric rear housing wall have occurred based on the receive signal strength information, user statistics, and/or phase and magnitude information. If a change is detected, the processing circuitry may adjust the matching circuitry to mitigate any potential antenna detuning as a result of the change.

Abstract: An electronic device such as a wristwatch may have a housing with metal sidewalls and a dielectric rear wall. The metal sidewalls may form an antenna ground for an antenna. The antenna may include an antenna resonating element formed from conductive traces patterned directly onto an interior surface of the dielectric rear wall. The conductive traces may define a slot at the dielectric rear wall. A coil and a sensor may be mounted to the dielectric rear wall within the slot. Radio-frequency transceiver circuitry may be coupled to the conductive traces and the antenna ground and may transmit and receive radio-frequency signals through the dielectric rear wall using the antenna. Wireless power receiver circuitry may use the coil to receive wireless power signals through the dielectric rear wall. The sensor may emit and/or receive light through a transparent window in the dielectric rear wall.

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: An electronic device such as a wristwatch may have a housing with metal portions such as metal sidewalls. The housing may form an antenna ground for an antenna. An antenna resonating element for the antenna may be formed from a stack of capacitively coupled component layers such as a display layer, touch sensor layer, and near-field communications antenna layer at a front face of the device. An additional antenna may be formed from a peripheral resonating element that runs along a peripheral edge of the device and the antenna ground. A rear face antenna may be formed using a wireless power receiving coil as a radio-frequency antenna resonating element or may be formed from metal antenna traces on a plastic support for light-based components.

Abstract: An electronic device such as a wristwatch may have a housing with metal portions such as metal sidewalls. The housing may form an antenna ground for an antenna. An antenna resonating element for the antenna may be formed from a stack of capacitively coupled component layers such as a display layer, touch sensor layer, and near-field communications antenna layer at a front face of the device. An additional antenna may be formed from a peripheral resonating element that runs along a peripheral edge of the device and the antenna ground. A rear face antenna may be formed using a wireless power receiving coil as a radio-frequency antenna resonating element or may be formed from metal antenna traces on a plastic support for light-based components.

Abstract: A housing for an electronic device is disclosed. The housing includes a first conductive component defining a first interface surface, a second conductive component defining a second interface surface facing the first interface surface, and a joint structure between the first and second interface surfaces. The joint structure includes a molded element forming a portion of an exterior surface of the housing, and a sealing member forming a watertight seal between the first and second conductive components. Methods of forming the electronic device housing are also disclosed.

Abstract: Methods and systems for controlling infiltration of ambient air into, and exfiltration of process gas out of, an organic Rankine system. A system comprises a first sealing mechanism configured to seal at least one shaft against exfiltration of a process gas when the turbomachine is operating. The system further comprises a second sealing mechanism configured to seal the at least one shaft against infiltration of ambient air when the system is in a standstill mode. The system further comprises one or more pressure sensors configured to detect a pressure of gas within the system to monitor whether infiltration of ambient air has occurred and a system purge is needed.

Abstract: An electronic device may have a display in a housing with a metal wall. An antenna may have an antenna ground formed from the wall and an antenna resonating element. Transceiver circuitry may be coupled to an antenna feed that extends between the antenna resonating element and the antenna ground. A return path may extend between the antenna resonating element and the antenna ground in parallel with the feed. The antenna resonating element may have segments that are coupled by a frequency dependent filter. At a first frequency, the filter may have a low impedance so that the antenna resonating element has a first effectively length. At a second frequency that is greater than the first frequency, the filter may have a high impedance so that the antenna resonating element has a second effective length that is shorter than the first effective length.

Abstract: A wireless adapter for a measurement device is provided. The wireless adapter includes a first universal serial bus (USB) port to couplably receive data from the measurement device. The wireless adapter includes a battery to power the measurement device via the first USB port. the wireless adapter includes a wireless module to wirelessly transmit the received data to an external computing device after processing by the wireless adapter.

Abstract: A wireless adapter for a measurement device is provided. The wireless adapter includes a first universal serial bus (USB) port to couplably receive data from the measurement device. The wireless adapter includes a battery to power the measurement device via the first USB port. the wireless adapter includes a wireless module to wirelessly transmit the received data to an external computing device after processing by the wireless adapter.

Abstract: Methods and systems for controlling infiltration of ambient air into, and exfiltration of process gas out of, an organic Rankine system. A system comprises a first sealing mechanism configured to seal at least one shaft against exfiltration of a process gas when the turbomachine is operating. The system further comprises a second sealing mechanism configured to seal the at least one shaft against infiltration of ambient air when the system is in a standstill mode. The system further comprises one or more pressure sensors configured to detect a pressure of gas within the system to monitor whether infiltration of ambient air has occurred and a system purge is needed.

Abstract: In one embodiment, a system includes a valve system switchable between a waste heat recovery position configured to direct incoming exhaust gas through an interior volume of an exhaust section of an engine and a bypass position configured to direct the incoming exhaust gas through a bypass duct to bypass a heat recovery boiler disposed within the interior volume. The system also includes an inert gas purging system configured to inject an inert gas into the interior volume to displace residual exhaust gas from the interior volume.