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.

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 flexible printed circuit and a rigid printed circuit mounted to the flexible printed circuit using a board-to-board (B2B) connector. The flexible printed circuit may include signal conductors coupled to one or more antennas on the rigid printed circuit through the B2B connector. A given one of the signal conductors may include a phase shifter segment on the flexible printed circuit and/or a thick impedance matching segment on the rigid printed circuit that help to form a smooth impedance transition from the flexible printed circuit to the rigid printed circuit and the antenna(s). The B2B connector may include signal contacts interleaved with a ground contacts. The B2B connector may include ground bars laterally surrounding the signal and ground contacts to maximize the strength of mechanical coupling between the flexible printed circuit and the rigid printed circuit.

Abstract: An electronic device may be provided with peripheral conductive housing structures having a first segment and a second segment. First and second antenna feeds may be coupled between the first segment and the ground structures. The first feed may convey signals in a first band and the second feed may convey signals in a second band. The first segment may be near-field coupled to a slot between the second segment and the ground structures. A first tuner may be coupled between the second segment and the ground structures and may adjust a resonance of the first segment in the first and second bands. A second tuner coupled to the first feed may perform impedance matching in the first band and aperture tuning in the second band. A third tuner coupled to the second feed may perform impedance matching in the second band and aperture tuning in the first band.

Abstract: An electronic device may be provided with peripheral conductive housing structures, a first antenna, and a second antenna. A gap may divide the housing structures into a first segment forming an arm of the first antenna and a second segment forming an arm of the second antenna. A first feed terminal may be coupled to the first segment and a second feed terminal may be coupled to the second segment. Switchable components may be coupled in parallel between the first and second feed terminals across the gap. The switchable components may be adjusted to tune the frequency response of the first and/or second antenna. The switchable components may have a first state in which only the first feed terminal feeds the first antenna and may have a second state in which both the first and second feed terminals feed the first antenna.

Abstract: An electronic device may be provided with an antenna resonating element on a first substrate that is mounted to a second substrate. A signal conductor may be coupled to a feed terminal on the antenna resonating element. The signal conductor may include impedance matching structures for the antenna. The impedance matching structures may include an open transmission line stub, a grounded transmission line stub, and a phase shifting segment. The impedance matching structures may configure the antenna to exhibit a wide bandwidth in an ultra-wideband (UWB) frequency band. If desired, the signal conductor may have a phase-shifting segment configured to match a non-50 Ohm impedance of a radio-frequency front end coupled to the signal conductor.

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 a housing and an antenna. The antenna may be on a first substrate mounted to a second substrate. The housing may include a dielectric cover, a conductive plate on the dielectric cover, and a mid-chassis. The second substrate may be mounted to the mid-chassis. The antenna may include a conductive patch extending from a segment of a conductive ring on the first substrate. The conductive plate may have an opening aligned with the conductive patch. The first substrate may be separated from the dielectric cover by an air gap. A conductive gasket may couple the conductive ring to the conductive plate and may laterally surround the air gap and the opening. The antenna may convey ultra-wideband (UWB) signals through the air gap, the opening, and the dielectric cover layer.

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 include first and second antennas formed from respective first and second segments of a housing. The first antenna may have a first feed coupled to the first segment by a first switch and coupled to the first segment by a first conductive trace. The second antenna may have a second feed coupled to the second segment by a second switch and coupled to the second segment by a second conductive trace. The first segment may be separated from the second segment by a single gap, a data connector may pass through the second segment, and the antennas may selectively cover a low band. Alternatively, the first segment may be separated from the second segment by a third segment and two gaps, the data connector may pass through the third segment, and the first and second antennas may concurrently cover 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 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 a curved cover layer and an antenna. The antenna may include a ground and a resonating element on a curved surface of a substrate. The curved surface may have a curvature that matches that of the cover layer. The resonating element may include first, second, and third arms fed by a feed. The first arm and a portion of the ground may form a loop antenna resonating element. The second arm and the first arm may form an inverted-F antenna resonating element, where a portion of the first arm forms a return path to the antenna ground for the inverted-F antenna resonating element. A gap between the first and second arms may form a distributed capacitance. The third arm may form an L-shaped antenna resonating element. The antenna may have a wide bandwidth from below 2.4 GHz to greater than 9.0 GHz.

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: An electronic device may have conductive sidewalls, a conductive turret, and a conductive bridge. The turret may be separated from the sidewalls by a slot. A display may be mounted to the turret and may include conductive display structures and a conductive ring that couples the display to the turret. An antenna in the device may have a radiating element formed from the conductive display structures, the ring, and the turret. The conductive bridge may form a short path across the slot to the sidewalls. The slot may define radiating edges of the radiating element. Integrating the antenna into the device in this way may maximize the bandwidth of the antenna by extending the antenna area to include the entire lateral area of the electronic device. This may also serve to maximize the active area of the display.

Abstract: An electronic device may have conductive sidewalls and a rear wall. The rear wall may have a first portion mounted to the sidewalls and a second portion protruding away from the first portion to define a cavity. A sensor board may be mounted within the cavity. A coil structure may be mounted within the cavity and surrounding the sensor board. An antenna may have an antenna ground separated from a patch element by an antenna volume. The patch element may include a first conductive trace on the first portion of the rear wall, a second conductive trace on the sensor board, and a conductive interconnect structure that couples the first conductive trace to the second conductive trace. The coil structure may be disposed outside of the antenna to minimize impact of the coil structure on performance of the antenna.

Abstract: An electronic device such as a wristwatch device may have a housing with metal sidewalls and a display module having conductive display structures. The conductive display structures may be separated from the sidewalls by a slot element for a first antenna that runs around the display module. A feed element for the first antenna may be coupled between the display structures and the sidewalls. An antenna resonating element for a second antenna may be disposed within the slot element. A printed circuit may include additional antenna elements for the second antenna. The antenna resonating element may extend away from the feed element for the first antenna to provide improved isolation between the two antennas. The first antenna may be operable to provide coverage for frequencies that are lower than frequencies for which the second antenna may be operable to provide coverage.

Abstract: A wireless communication system comprises a base station and one or more relay docks and transmits directional wave signals between components using high frequency waves, such as millimeter waves. A beam forming decision engine utilizes position information collected from one or more position or motion sensors of a user device to determine a direction in which to form a directional wave signal being transmitted between components of the wireless communication system.

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 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.