Abstract: An electronic device may be provided with wireless circuitry. Control circuitry may be used to adjust transmit power levels for wireless signals, may be used to tune antennas, and may be used to adjust other settings for the wireless circuitry. The electronic device may have a coupler interposed between an antenna and wireless transceiver circuitry. The coupler and a receiver within the transceiver circuitry may be used to make measurements on tapped antenna signals such as transmitted signals and signals reflected from the antenna. By analyzing the tapped antenna signals, S-parameter phase and magnitude information may be gathered that provides insight into whether the electronic device is operating properly and whether an external object is adjacent to the antenna. If an external object is present, the electronic device may limit wireless transmit power and may adjust tunable components in the antenna to compensate for detuning from the external object.

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 have a housing with metal sidewalls and a display having conductive display structures. The display structures may be separated from the sidewalls by a slot for an antenna that runs around the display module. A conductive interconnect may be coupled between the sidewalls and the display structures. A feed and tuning element may be coupled between the display structures and the sidewalls. A first length of the slot from the interconnect to the tuning element may radiate in a satellite band and a cellular band. A second length of the slot from the interconnect to the feed may radiate in a 2.4 GHz band. Harmonics of the second length may radiate in bands at and above 5.0 GHz. If desired clip and blade structures may form conductive paths for coupling antenna elements.

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 antenna signals through the dielectric cover. The dielectric cover may have a surface that faces the phased antenna array and may have a curvature. The antenna elements of the phased antenna array may be formed on a dielectric substrate. The dielectric substrate may have one or more thinned regions between antenna elements of the phased antenna array to reduce surface wave interference between adjacent antennas. The dielectric substrate may have a smaller thickness in the thinned region than in the regions under the antenna elements. The dielectric substrate may be totally removed in the thinned region.

Abstract: An electronic device may include a phased antenna array mounted in a conductive cavity for conveying radio-frequency signals above 10 GHz. The cavity may include sidewalls extending from a rear wall. The array may include rectangular patches each having first and second perpendicular edges. Each of the first edges in the array may be aligned with a first axis. Each of the second edges in the array may be aligned with a second axis perpendicular to the first axis. The first and second axes may be oriented at 45 degrees with respect to each of the sidewalls of the cavity. Each patch may be fed using first and second positive antenna feed terminals that cover orthogonal linear polarizations. The cavity may prevent interference while symmetrically loading the impedance of both the first and second positive antenna feed terminals in each patch.

Abstract: An electronic device such as a wristwatch may be provided with wireless circuitry and a display having a display module and a cover layer. The display module may include a dielectric layer. Touch sensor electrodes may be formed from conductive traces on the dielectric layer. An antenna may be embedded within the display module. The antenna may include an antenna resonating element formed from a grid of intersecting conductive traces on the dielectric layer. The grid may have edges that define a lateral outline of the antenna resonating element. The outline may have a length that configures the antenna to radiate at a desired frequency. The antenna resonating element may be formed from indium tin oxide and may be substantially transparent.

Abstract: An electronic device may be provided with wireless circuitry. The wireless circuitry may include one or more antenna structures and transceiver circuitry such as millimeter wave transceiver circuitry. Antenna structures in the wireless circuitry may include patch antennas that are organized in a phased antenna array. Each patch antenna may include an antenna resonating element and a parasitic element. The parasitic element for the patch antenna may have dielectric-filled openings formed between coplanar parasitic conductors. The parasitic conductors may include a central parasitic conductor, four rectangular parasitic conductors formed around the central parasitic conductor, and corner parasitic conductors formed at the corners of the parasitic element. The corner parasitic conductors may be non-rectangular. For example, the corner parasitic conductors may have first and second perpendicular edges and a straight or curved third edge that joins the first and second edges.

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: An electronic device may be provided with wireless circuitry. The wireless circuitry may include multiple antennas and transceiver circuitry. The antennas may include antenna structures at opposing first and second ends of the electronic device. The antenna structures at a given end of the device may include antenna structures that are shared between multiple antennas. The electronic device may include a first antenna with an inverted-F antenna resonating element formed from portions of a peripheral conductive housing structure and may have an antenna ground that is separated from the antenna resonating element by a gap. A return path may bridge the gap. The electronic device may also include a second antenna that includes the antenna ground and an additional antenna resonating element. The antenna resonating element of the second antenna may be parasitically coupled to the return path of the inverted-F antenna at given frequencies.

Abstract: An electronic device may include control circuitry, sensors, and wireless circuitry having antennas. The sensors may generate sensor data that is used by the control circuitry to identify an operating environment for the device. The sensor data may include a grip map generated by a touch-sensitive display, infrared facial recognition image signals or other image signals, an angle of arrival of sound received by a set of microphones, impedance data from an impedance sensor, and any other desired sensor data. The control circuitry may use the sensor data, radio-frequency spatial ranging data, information about whether audio is being played over an ear speaker, and/or information about communications protocols in use to identify the operating environment. The control circuitry may adjust antenna settings for the wireless circuitry based on the identified operating environment to ensure that the antennas operate with satisfactory antenna efficiency regardless of operating conditions.

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. The antenna may include a feed coupled to a transmission line having a signal conductor. The feed may include first and second positive terminals on the first segment and a third positive terminal on the second segment. An adjustable component may be coupled between the first and third terminals. The signal conductor may be coupled to the first terminal. A wide conductive trace may be coupled between the signal conductor and the second terminal. A switch may be interposed on the signal conductor. The second terminal may cover a cellular low band when the switch is open. The first terminal may cover the cellular low band and higher bands when the switch is closed.

Abstract: Electronic devices may be provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and first and second antennas. An electronic device may include a housing. The first antenna may be located at an upper end of the housing and the second antenna may be located at a lower end of the housing. A peripheral conductive member may run around the edges of the housing and may be used in forming the first and second antennas. The radio-frequency transceiver circuitry may have a transmit-receive port and a receive port. Switching circuitry may connect the first antenna to the transmit-receive port and the second antenna to the receiver port or may connect the first antenna to the receive port and the second antenna to the transmit-receive port.

Abstract: An electronic device such as a wristwatch may have a housing with metal sidewalls and a display having conductive display structures. The display structures may be separated from the sidewalls by a slot for an antenna that runs around the display module. A conductive interconnect may be coupled between the sidewalls and the display structures. A feed and tuning element may be coupled between the display structures and the sidewalls. A first length of the slot from the interconnect to the tuning element may radiate in a satellite band and a cellular band. A second length of the slot from the interconnect to the feed may radiate in a 2.4 GHz band. Harmonics of the second length may radiate in bands at and above 5.0 GHz. If desired, the tuning element may be omitted, and the antenna may be coupled to separate low band and high band matching circuits.

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 have hybrid antennas that include slot antenna resonating elements formed from slots in a ground plane and planar inverted-F antenna resonating elements. The planar inverted-F antenna resonating elements may each have a planar metal member that overlaps one of the slots. A return path and feed may be coupled in parallel between the planar metal member and the ground plane. Adjustable circuits such as tunable inductors may be used to tune the hybrid antennas. Adjustable circuits may bridge the slots in hybrid antennas and may be included in return paths that are coupled between the planar metal members of the planar inverted-F antenna resonating elements and the ground plane. A slot may be selectively divided to from two slots using switching circuitry.

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 may be provided with wireless circuitry, a conductive housing, and a display. The display may have an active area that displays image data and an inactive area that does not display image data. The active area may completely surround the inactive area at a front face of the device. A speaker port may be aligned with the inactive area and may emit sound through the inactive area. The wireless circuitry may include first and second antenna arrays. The first array may be configured to transmit and receive wireless signals at frequencies between 10 GHz and 300 GHz through the inactive area of the display. The second array may be configured to transmit and receive wireless signals at frequencies between 10 GHz and 300 GHz through a slot in a rear wall of the conductive housing. Control circuitry may perform beam steering using the first and second arrays.

Abstract: An electronic device may include antennas, a ground, and a housing. First and second gaps in the housing may define a segment that forms a resonating element for a first antenna. First, second, third, and fourth antenna feeds may be coupled between the segment and ground. Control circuitry may control adjustable components to place the device in first, second, third, or fourth modes. In the first and second modes, the first and fourth feeds convey signals at the same frequency using a multiple-input and multiple-output scheme while the second and third feeds are inactive. In the third mode, the second feed is active and the first, third, and fourth feeds are inactive. In the fourth mode, the third feed is active and the first, second, and fourth antenna feeds are inactive. Isolating return paths may be coupled between the segment and ground in the first and second modes.

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 consumer electronic product includes a switchable inductor array coupled to the RF antenna, the switchable inductor array comprising inductive elements and a switch circuit coupled to the inductor array to select at least one of the inductive elements and couple the selected inductive element with the RF antenna. The product can further include an assembly having a mesh that is strengthened by a stiffener. A multi-layer adhesive have a conductive layer that can be used to shield the RF antenna and adhesive layers that can provide adhesion between the stiffener and the housing of the product. The assembly can be covered by a cowling that is made of metal to provide further shielding. To reduce potential coupling between the RF antenna and the cowling, the cowling can have a portion that is formed of plastic to distance its metal portion from the antenna.