Abstract: An electronic device may be provided with an antenna module having a substrate. An antenna may be disposed on the substrate. The antenna may have a directly fed patch and parasitic patches. The antenna may be fed by a feed via. The parasitic patches may include a first layer of parasitic patches separated by a gap overlapping the directly fed patch. The parasitic patches may include an additional parasitic patch formed in a second layer. The additional parasitic patch may overlap the gap. A floating ground via may couple a center of the additional parasitic patch and a center of the directly fed patch to a landing pad in a ground layer. The landing pad may short the via to the ground layer at the radiating frequency of the antenna. The landing pad may be electrically floating at DC frequencies.

Abstract: An electronic device may be provided with peripheral conductive housing structures and a rear housing wall. The electronic device may have a display mounted to the peripheral conductive housing structures opposite the rear housing wall. The rear housing wall may have a dielectric cover layer and a conductive support plate that extends along the dielectric cover layer. The electronic device may have an antenna that radiates through the dielectric cover layer. The antenna may have a slot antenna resonating element that includes a first slot between the support plate and the peripheral structures and may include a second slot extending from the first slot into the support plate. A conductive interconnect may couple the support plate to the peripheral conductive housing structures at an end of the first slot. The antenna may be fed at a feed protrusion that extends into the second slot.

Abstract: An electronic device may be provided with an antenna that radiates through a rear housing wall in multiple frequency bands. The antenna may have one or more directly fed patches and one or more indirectly fed patches that are indirectly fed by the directly fed patch(es). One or more of the patches may be shorted to ground traces through the substrate using conductive vias. The antenna may be provided with a dielectric block mounted to the substrate. The patches may be sandwiched between the substrate and the dielectric block. The dielectric block may have a higher dielectric constant than the substrate. The dielectric block may contribute one or more dielectric resonator antenna (DRA) modes to the resonances of the antenna. In these implementations, the patches in the antenna resonating element may form a feed probe for the dielectric block.

Abstract: An electronic device may be provided with sidewalls and a conductive plate. A segment of the sidewalls may form a radiating arm of an antenna. A display may be mounted to the sidewalls. The display may include a conductive frame and a flexible printed circuit. The flexible circuit may have a bend. Conductive foam may short a conductive trace on the flexible circuit to the conductive frame near the bend. Low injection pressure overmolding (LIPO) may be molded over the flexible circuit, the foam, and the frame. A conductive spring may short the frame to the conductive plate. The spring may include a wider and/or thinner portion that optionally includes one or more notches for reducing its inductance. The conductive plate, the spring, the frame, the foam, and the conductive trace may form part of the antenna ground for the antenna.

Abstract: An electronic device may be provided with wireless circuitry and a housing having peripheral conductive housing structures. The wireless circuitry may include first and second antennas. The first antenna may have a resonating element arm formed from a first segment of the peripheral conductive housing structures. The second antenna may have a resonating element arm formed from a second segment of the peripheral conductive housing structures separated from the first segment by a gap. Switchable short paths may be coupled between the second segment and ground on opposing sides of an antenna feed for the second antenna and/or may be coupled between the first and second segments and ground on opposing sides of the gap. Additionally or alternatively, a switch may be coupled between the first and second segments across the gap and a tuning component may couple the second segment to the ground structures.

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 wireless radio-frequency 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 curvature of the second surface may include one or more recessed regions of the dielectric cover. The one or more recessed regions of the second surface may serve to maximize and broaden the coverage area for the phased antenna array. The first surface may be conformal to other structures in the electronic device.

Abstract: An electronic device may have a cover layer and an antenna. A dielectric adapter may have a first surface coupled to the antenna and a second surface pressed against the cover layer. The cover layer may have a three-dimensional curvature. The second surface may have a curvature that matches the curvature of the cover layer. Biasing structures may exert a biasing force that presses the antenna against the dielectric adapter and that presses the dielectric adapter against the cover layer. The biasing force may be oriented in a direction normal to the cover layer at each point across dielectric adapter. This may serve to ensure that a uniform and reliable impedance transition is provided between the antenna and free space through the cover layer over time, thereby maximizing the efficiency of the antenna.

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 peripheral conductive housing structures having first and second segments. The device may include an antenna having a resonating arm formed from the first segment, an antenna ground, and a tuning element. The tuning element may have first, second, and third terminals. The first terminal may be coupled to the second segment. The antenna may have a switchable loop path that includes a first path from the second terminal to the first segment, a second path from first segment to a first point on the antenna ground, a portion of the antenna ground from the first point to a second point, and a third path from the second point to the third terminal. The tuning element may selectively activate the switchable loop path to boost performance of the antenna in a frequency band between 3300 MHz and 5000 MHz when needed.

Abstract: A head-mounted device may have a head-mounted housing. The head-mounted housing may have rear-facing displays that display images for a user. The images are viewable from eye boxes while the head-mounted device is being worn by the user. A peripheral conductive member may run along a peripheral edge of the front face of the housing. Dielectric-filled gaps may divide the peripheral conductive member into elongated conductive segments. The conductive segments may form antenna resonating elements for antennas on the front face. Radio-frequency transceiver circuitry such as cellular telephone transceiver circuitry may be coupled to the antennas.

Abstract: A head-mounted device may have a head-mounted housing that is configured to be worn on a head of a user. While the head-mounted device is being worn, left and right displays in optical modules in the head-mounted device may provide images to eye boxes located rearward of the head-mounted device. A forward-facing publicly viewable display on a front portion of the head-mounted device may be covered with a transparent housing portion forming a display cover layer. Millimeter wave antennas may be mounted under a dielectric member that is interposed between the antennas and an edge portion of the transparent housing portion. The antennas may have planar outer surfaces. The dielectric member may have a planar surface separated from the planar outer surfaces by air gaps and a curved outer surface.

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 include an antenna disposed on a substrate. The antenna may include a ring of conductive traces, a fed arm, and an unfed arm. The fed arm and the unfed arm may extend from opposing segments of the ring. The ring may be coupled to ground by fences of conductive vias extending through the substrate. The first arm may have a first radiating edge. The second arm may have a second radiating edge. The first radiating edge may be separated from the second radiating edge by a gap. The first arm may indirectly feed the second arm via near-field electromagnetic coupling across the gap. The first and second arms may collectively radiate in an ultra-wideband (UWB) frequency band.

Abstract: An electronic device may include first and second phased antenna arrays and a triplet of first, second, and third ultra-wideband antennas. An antenna module in the device may include a dielectric substrate. The first and second arrays and the triplet may be formed on the dielectric substrate. The third and second ultra-wideband antennas may be separated by a gap. The first array may be laterally interposed between the third and second ultra-wideband antennas within the gap. The third ultra-wideband antenna may be laterally interposed between the first phased antenna array and at least some of the second array. An integrated circuit may be mounted to the dielectric substrate using an interposer. The antenna module may occupy a minimal amount of space within the device and may be less expensive to manufacture relative to scenarios where the arrays and the ultra-wideband antennas are formed on separate substrates.

Abstract: An electronic device may be provided with a phased antenna array that radiates at a frequency greater than 10 GHz through a display. The array may include a dielectric resonator antenna having a dielectric column. The dielectric column may have a first surface mounted to a circuit board and a second surface that faces the display. A conductive cap may be formed on the second surface. The conductive cap may allow the dimensions of dielectric column to be reduced while still allowing the dielectric resonator antenna to cover a frequency band of interest. If desired, the phased antenna array may include multiple sets of dielectric resonator antennas for covering different frequency bands. The sets may have different dielectric column heights and/or different conductive cap sizes.

Abstract: An electronic device may be provided with a first antenna fed by a first path and a second antenna fed by a second path. A first coupler may be disposed on the first path, a second coupler may be disposed on the second path, and a feedback path may couple the couplers to a receiver. A low-pass filter may be disposed on the second path. The first antenna may transmit signals in a low band. Some of the signals may couple onto the second antenna. The second coupler may pass the coupled signals to the receiver. Control circuitry may generate a scattering parameter value characterizing the coupling of the signals from the first antenna onto the second antenna. The scattering parameter value may be used to determine when to switch the first antenna out of use and the second antenna into use for covering the low band.

Abstract: An electronic device may have a phased antenna array. An antenna in the array may include a rectangular patch element with diagonal axes. The antenna may have first and second antenna feeds coupled to the patch element along the diagonal axes. The antenna may be rotated at a forty-five degree angle relative to other antennas in the array. The antenna may have one or two layers of parasitic elements overlapping the patch element. For example, the antenna may have a layer of coplanar parasitic patches separated by a gap. The antenna may also have an additional parasitic patch that is located farther from the patch element than the layer of coplanar parasitic patches. The additional parasitic patch may overlap the patch element and the gap in the coplanar parasitic patches. The antenna may exhibit a relatively small footprint and minimal mutual coupling with other antennas in the array.

Abstract: An electronic device may be provided with an antenna having a resonating element and a light source module mounted to a flexible printed circuit and a metal cowling. The module may emit light through a rear housing wall. The printed circuit may be interposed between the metal cowling and a conductive support plate in the rear housing wall. The printed circuit may include a ground trace coupled to the resonating element. A dimpled pad may couple the ground trace to the support plate. Compressive foam may be used to exert a force against the flexible printed circuit that presses the dimpled pad against the conductive support plate. The ground trace and the dimpled pad may form a return path to ground for the resonating element. The dimpled pad may occupy less height within the device than other structures such as metal springs.

Abstract: An electronic device may be provided with peripheral conductive housing structures having first and second segments. A flexible printed circuit may have a first tail that extends along the first and second segments and a second tail that extends along the first segment. A conductive trace on the first tail may be coupled to an antenna feed terminal on the second segment. A conductive trace on the second tail may couple the conductive trace on the first tail to the first segment. A tuner and filters may be disposed on the flexible printed circuit and may be coupled to the conductive traces. The conductive trace on the second tail may have a tapered width. An antenna in the device may have a resonating element that includes both the first and second segments, thereby allowing the antenna to exhibit a wide bandwidth from 1.1-5 GHz.

Abstract: An electronic device may be provided with a sensor module and an antenna having an antenna arm, ground structures, and a tuner. The tuner may be mounted to a printed circuit overlapping the sensor module. A spring may be mounted to the printed circuit and may couple the tuner to a conductive chassis of the sensor module. The sensor module may include optical sensors that gather sensor data through a display and may form ground paths from the tuner to the ground structures. Conductive interconnect structures such as springs may exert biasing forces in different directions to couple the ground paths to different layers of the ground structures. This may serve to couple the antenna to the ground structures as close as possible to the tuner, thereby maximizing antenna performance, despite the presence of the sensor module.