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 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 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 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 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 peripheral conductive housing structures having a segment that forms a resonating element for an antenna. A speaker may be mounted to a mid-chassis of the electronic device. A printed circuit may be mounted to the speaker and may have a ground trace for the antenna. A conductive spring may extend through the printed circuit and the speaker to couple the ground trace to the mid-chassis. A conductive contact pad may be welded to an aluminum layer such as an aluminum layer used to form the mid-chassis. A conductive spring such as the conductive spring coupled to the ground traces may press against the contact pad. The contact pad may include gold or nickel-plated stainless steel. The contact pad may provide a strong electrical connection between the conductive spring and the aluminum layer.

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 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 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 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 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 be provided with an antenna module. A phased antenna array of dielectric resonator antennas may be disposed within the antenna module. The dielectric resonator antennas may include dielectric columns excited by feed probes. A flexible printed circuit may include transmission lines coupled to the feed probes. The flexible printed circuit may have a first end coupled to the antenna module and extending towards peripheral conductive housing structures forming an additional antenna and a second end coupled to transceiver circuitry. Ground traces on the flexible printed circuit may be shorted to ground structures at the first and second ends to improve the antenna efficiency of the additional antenna. The flexible printed circuit may include an elongated slot with overlapping conductive structures and laterally surrounded by a fence of conductive vias to improve the flexibility of the flexible printed circuit while providing satisfactory antenna performance.

Abstract: An electronic device may be provided with wireless circuitry and a housing with upper and lower ends. The lower end may include first and second open slot antennas that are directly fed by respective feeds and that radiate in a cellular ultra-high band. The lower end may also include first and second inverted-F antennas. The upper end may include third and fourth inverted-F antennas. The first inverted-F antenna may have a first feed that conveys currents below 2700 MHz and a second feed that conveys antenna currents in the cellular ultra-high band, a wireless local area network band, and/or ultra-wideband frequency bands. If desired, the upper end may include a third open slot antenna that is directly fed by a corresponding antenna feed and that radiates in the cellular ultra-high band and/or in the ultra-wideband frequency bands.

Abstract: An electronic device may be provided with a housing and an antenna having a resonating element. The resonating element may have first and second arms extending from opposing sides of a feed. The first arm and a portion of the housing may radiate in a cellular ultra-high band. The first arm may have a fundamental mode that radiates in a first ultra-wideband (UWB) communications band at 6.5 GHz. The second arm may have a fundamental mode that radiates in a 5.0 GHz wireless local area network band. The first and second arms may have a harmonic mode that radiates in a second UWB communications band at 8.0 GHz. The antenna may convey radio-frequency signals in each of these communications bands without the need for adjusting components in the antenna to switch between the UWB communications bands.

Abstract: An electronic device may be provided with an antenna module. A phased antenna array of dielectric resonator antennas may be disposed within the antenna module. The dielectric resonator antennas may include dielectric columns excited by feed probes. A flexible printed circuit may include transmission lines coupled to the feed probes. The flexible printed circuit may have a first end coupled to the antenna module and extending towards peripheral conductive housing structures forming an additional antenna and a second end coupled to transceiver circuitry. Ground traces on the flexible printed circuit may be shorted to ground structures at the first and second ends to improve the antenna efficiency of the additional antenna. The flexible printed circuit may include an elongated slot with overlapping conductive structures and laterally surrounded by a fence of conductive vias to improve the flexibility of the flexible printed circuit while providing satisfactory antenna performance.

Abstract: An electronic device may be provided with wireless circuitry and a housing with upper and lower ends. The lower end may include first and second open slot antennas that are directly fed by respective feeds and that radiate in a cellular ultra-high band. The lower end may also include first and second inverted-F antennas. The upper end may include third and fourth inverted-F antennas. The first inverted-F antenna may have a first feed that conveys currents below 2700 MHz and a second feed that conveys antenna currents in the cellular ultra-high band, a wireless local area network band, and/or ultra-wideband frequency bands. If desired, the upper end may include a third open slot antenna that is directly fed by a corresponding antenna feed and that radiates in the cellular ultra-high band and/or in the ultra-wideband frequency bands.

Abstract: A device with near-field communications (NFC) capabilities is provided. A housing may include first and second segments and a support plate separated from the segments by a slot. A first inductor may be coupled between the first segment and the plate. A second inductor may be coupled between the second segment and the plate. A transceiver may have a first signal terminal coupled to the first segment over a first path and a second signal terminal coupled to the second segment over a second path. The transceiver may convey differential signals in an NFC band over a loop path for an NFC antenna that includes the first conductive path, the first segment, the first inductor, a portion of the plate between the first and second inductors, the second inductor, the second segment, and the second conductive path. This may optimize wireless performance and volume for the NFC antenna.

Abstract: An electronic device may be provided with an antenna having a resonating element. The resonating element may have first and second arms extending from opposing sides of a feed. The first arm may have a fundamental mode that radiates in a first communications band such as a 5.0 GHz wireless local area network band. The second arm may have a fundamental mode that radiates in a second communications band such as one or more cellular ultra-high bands. The second resonating element arm may have a harmonic mode that radiates in first and second ultra-wideband (UWB) communications bands. The antenna may include a tunable component that is adjustable between first and second states. The second arm may radiate in the first UWB communications band while the tunable component is in the first state and in the second UWB communications band while the tunable component is in the second state.

Abstract: An electronic device may be provided with a housing and an antenna having a resonating element. The resonating element may have first and second arms extending from opposing sides of a feed. The first arm and a portion of the housing may radiate in a cellular ultra-high band. The first arm may have a fundamental mode that radiates in a first ultra-wideband (UWB) communications band at 6.5 GHz. The second arm may have a fundamental mode that radiates in a 5.0 GHz wireless local area network band. The first and second arms may have a harmonic mode that radiates in a second UWB communications band at 8.0 GHz. The antenna may convey radio-frequency signals in each of these communications bands without the need for adjusting components in the antenna to switch between the UWB communications bands.

Abstract: An electronic device may be provided with an antenna having a resonating element. The resonating element may have first and second arms extending from opposing sides of a feed. The first arm may have a fundamental mode that radiates in a first communications band such as a 5.0 GHz wireless local area network band. The second arm may have a fundamental mode that radiates in a second communications band such as one or more cellular ultra-high bands. The second resonating element arm may have a harmonic mode that radiates in first and second ultra-wideband (UWB) communications bands. The antenna may include a tunable component that is adjustable between first and second states. The second arm may radiate in the first UWB communications band while the tunable component is in the first state and in the second UWB communications band while the tunable component is in the second state.