Abstract: An electronic device may be provided with wireless circuitry. The wireless circuitry may include antennas. The antennas may include phased antenna arrays for handling millimeter wave signals. Antennas may be located in antenna signal paths. The antenna signal paths may include adjustable components such as adjustable filters, adjustable gain amplifiers, and adjustable phase shifters. Circuitry may be incorporated into an electronic device to facilitate wireless self-testing operations. Wireless self-testing may involve use of one antenna to transmit an over-the-air antenna test signal that is received by another antenna. The circuitry that facilitates the wireless self-testing operations may include couplers, adjustable switches for temporarily shorting antenna signal paths together, mixers for mixing down radio-frequency signals to allow digitization with analog-to-digital converters, and other circuitry for supporting self-testing operations.

Abstract: An electronic device may be provided with a dielectric cover layer, a dielectric substrate, and a phased antenna array on the dielectric substrate for conveying millimeter wave signals through the dielectric cover layer. The array may include conductive traces mounted against the dielectric layer. The conductive traces may form patch elements or parasitic elements for the phased antenna array. The dielectric layer may have a dielectric constant and a thickness selected to form a quarter wave impedance transformer for the array at a wavelength of operation of the array. The substrate may include fences of conductive vias that laterally surround each of the antennas within the array. When configured in this way, signal attenuation, destructive interference, and surface wave generation associated with the presence of the dielectric layer over the phased antenna array may be minimized.

Abstract: An electronic device may be provided with a dielectric cover layer and a conductive layer on the dielectric cover layer. The conductive layer may define an opening. A dielectric spacer may be mounted to the cover layer within the opening. A substrate may be mounted to the spacer. Vertical conductive structures may extend from the conductive layer to the substrate and may laterally surround the spacer. A phased antenna array may be formed on the substrate and aligned with the opening. The cover layer may have a dielectric constant and thickness that are selected to form a quarter wave impedance transformer for the array at a wavelength of operation of the array. The spacer and the conductive structures may exhibit a cavity resonance at the wavelength. The array and the conductive structures may radiate radio-frequency signals at millimeter wave frequencies through the dielectric cover layer.

Abstract: An electronic device may be provided with wireless circuitry. The wireless circuitry may include one or more antennas and transceiver circuitry such as millimeter wave transceiver circuitry. The antennas may be formed from metal traces on printed circuits. A flexible printed circuit may have an area on which the transceiver circuitry is mounted. Protruding portions may extend from the area on which the transceiver circuitry is mounted and may be separated from the area on which the transceiver circuitry is mounted by bends. Antenna resonating elements such as patch antenna resonating elements and dipole resonating elements may be formed on the protruding portions and may be used to transmit and receive millimeter wave antenna signals through dielectric-filled openings in a metal electronic device housing or a dielectric layer such as a display cover layer formed from glass or other dielectric.

Abstract: This is directed to connecting two or more elements using an intermediate element constructed from a material that changes between states. An electronic device can include one or more components constructed by connecting several elements. To provide a connection having a reduced or small size or cross-section and construct a component having high tolerances, a material can be provided in a first state in which it flows between the elements before changing to a second state in which it adheres to the elements and provides a structurally sound connection. For example, a plastic can be molded between the elements. As another example, a composite material can be brazed between the elements. In some cases, internal surfaces of the elements can include one or more features for enhancing a bond between the elements and the material providing the interface between the elements.

Abstract: An electronic device may be provided with a sidewall, a display module separated from the sidewall by a gap a display cover, a conductive bucket mounted to the display cover within the gap, and a phased antenna array mounted to the bucket for conveying millimeter wave signals through the display cover. The sidewall may form part of an antenna for conveying non-millimeter wave signals. The array may include resonating elements on a substrate. The resonating elements may be fed using feed terminals coupled to alternating sides of the resonating elements. Dielectric layers having a dielectric constant lower than that of the display cover may be provided on a surface of the display cover within the bucket. The array may operate with satisfactory efficiency despite the small amount of available space within the device, electromagnetic interference from the sidewall and the display module, and dielectric loading by the display cover.

Abstract: A computer stylus may be provided that includes an elongated body with a tip and an opposing end coupled together by a shaft that includes a metal tube. The stylus may include a substrate at the end of the elongated body and conductive traces on the substrate. The traces may form a sensor electrode for a sensor and an antenna resonating element for an antenna in the stylus. The sensor may include an electrode that gathers sensor signals. Control circuitry may wirelessly transmit the sensor signals to external equipment using the antenna. The sensor electrode may be coupled to the metal tube by a filter. The filter may form an open circuit at radio-frequencies and a short circuit at the frequency of the sensor signals. The filter may mitigate deterioration in wireless performance of the antenna associated with the presence of the sensor.

Abstract: An electronic device may include first, second, and third antennas and conductive housing structures. The first, second, and third antennas may each include slots having open ends defined by gaps in the conductive housing structures. The second antenna may be interposed between the first and third antennas. The first and second antennas may convey signals at the same frequencies. The third antenna may convey signals at a lower frequency than the first and second antennas. A switch may be coupled across the third slot and may have a first state at which the switch forms a closed end of the third slot and a second state at which the third slot has two opposing open ends. Control circuitry may selectively activate one of two feeds for the third antenna and may adjust the switch so that the third antenna exhibits satisfactory antenna efficiency regardless of environmental conditions for the device.

Abstract: An electronic device may include a conductive housing and an antenna. The antenna may include an arm formed from a first segment of the housing. A gap may separate the first segment from a second segment. Respective first and second slots may separate an antenna ground from the first and second segments. The antenna may have a first positive antenna feed terminal on the first segment and a second positive antenna feed terminal on the second segment. A transmission line may include a signal conductor having a first branch coupled to the first positive antenna feed terminal and a second branch coupled to the second positive antenna feed terminal. A switch may be interposed on the second branch for switching the antenna between a first mode in which the second slot is directly fed and a second mode in which the second segment is indirectly fed by the first segment.

Abstract: An electronic device such as a wristwatch may be provided with a phased antenna array for conveying first signals at a first frequency between 10 GHz and 300 GHz and a non-millimeter wave antenna for conveying second signals at a second frequency below 10 GHz. The device may include conductive housing sidewalls and a display. Conductive structures in the display and the conductive housing sidewalls may define a slot element in the non-millimeter wave antenna. The phased antenna array may be mounted within the slot element, aligned with a spatial filter in the display, or aligned with a dielectric window in the conductive housing sidewalls. Control circuitry may process signals transmitted by the phased antenna array and a reflected version of the transmitted signals that has been received by the phased antenna array to detect a range between the device and an external object.

Abstract: An electronic device may be provided with a phased antenna array for conveying millimeter wave signals. The array may be mounted to a substrate that includes transmission line layers having a first dielectric permittivity and antenna layers having a second dielectric permittivity that is less than the first dielectric permittivity. A ground plane may be interposed between the antenna layers and the transmission line layers. The array may be mounted to the antenna layers and transceiver circuitry may be mounted to the transmission line layers. Transmission line traces may be formed on the transmission line layers. The relatively high permittivity of the first set of dielectric layers may allow the transmission line traces to be routed relatively close together with minimal electromagnetic interference. The relatively low permittivity of the second set of dielectric layers may allow the array to operate with satisfactory antenna efficiency, gain, and bandwidth.

Abstract: An electronic device may include an antenna having a resonating element, an antenna ground, and a feed. First and second tunable components may be coupled to the resonating element. Adjustable matching circuitry may be coupled to the feed. Control circuitry may use the first tunable component to tune a midband antenna resonance when sensor circuitry identifies that the device is being held in a right hand and may use the second tunable component to tune the midband resonance when the sensor circuitry identifies that the device is being held in a left hand. For tuning a low band resonance, the control circuitry may place the antenna in different tuning states by sequentially adjusting a selected one of the matching circuitry and the tunable components, potentially reverting to a previous tuning state at each step in the sequence. This may ensure that antenna efficiency is satisfactory regardless of antenna loading conditions.

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: An electronic device may be provided with antenna structures and control circuitry. The antenna structures may include an antenna resonating element arm, an antenna ground, and an antenna feed coupled between the antenna resonating element arm and the antenna ground. The electronic device may include a tunable component configured to tune a frequency response of the antenna structures. The electronic device may also include a substrate, a radio-frequency transceiver on the substrate, control circuitry configured to generate control signals, a flexible printed circuit, and a connector. The connector may mechanically secure the flexible printed circuit to the substrate and may be electrically coupled to the transceiver and the control circuitry. The flexible printed circuit may include a radio-frequency transmission line coupled between the antenna feed and the connector and a control signal path coupled between the tunable component and the connector.

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 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 such as a wristwatch may be provided with a wireless local area network (WLAN) transceiver, satellite receiver, and cellular transceiver. A first antenna may include a radiating slot between a conductive housing wall and a display module. A second antenna may include conductive structures that radiate through a rear face of the device. The WLAN transceiver and the satellite receiver may be coupled to the first antenna. A switch may be coupled between the cellular transceiver and the first and second antennas. Control circuitry may adjust the switch to route signals between the cellular transceiver and a selected one of the first and second antennas based on wireless performance metric data so that the antenna exhibiting superior wireless performance at cellular telephone frequencies is used for cellular telephone communications regardless of environmental conditions.

Abstract: Electronic devices may be provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and antenna structures. The antenna structures may form a dual arm inverted-F antenna. The antenna may have a resonating element formed from portions of a peripheral conductive electronic device housing member and may have an antenna ground that is separated from the antenna resonating element by a gap. A short circuit path may bridge the gap. An antenna feed may be coupled across the gap in parallel with the short circuit path. Low band tuning may be provided using an adjustable inductor that bridges the gap. The antenna may have a slot-based parasitic antenna resonating element with a slot formed between portions of the peripheral conductive electronic device housing member and the antenna ground. An adjustable capacitor may bridge the slot to provide high band tuning.

Abstract: An electronic device may be provided with wireless circuitry. The wireless circuitry may include one or more antennas. The antennas may include millimeter wave antenna arrays. Non-millimeter-wave antennas such as cellular telephone antennas may have conductive structures separated by a dielectric gap. In a device with a metal housing, a plastic-filled slot may form the dielectric gap. The conductive structures may be slot antenna structures, inverted-F antenna structures such as an inverted-F antenna resonating element and a ground, or other antenna structures. The plastic-filled slot may serve as a millimeter wave antenna window. A millimeter wave antenna array may be mounted in alignment with the millimeter wave antenna window to transmit and receive signals through the window. Millimeter wave antenna windows may also be formed from air-filled openings in a metal housing such as audio port openings.

Abstract: An electronic device may include a ring-shaped housing member defining an interior volume. The ring-shaped housing member may be configured to receive electronic device components. The ring-shaped housing member may include a first element comprising an angled region, and a second element comprising an angled region. A first intermediate element may be placed between the first and second elements, where the intermediate element is secured to internal surfaces of each of the first and second elements such that the first and second elements do not overlap. The first intermediate element may fasten the first and second elements to one another, and electrically isolate the first and second elements from one another.