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: 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 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 a dielectric cover and a phased antenna array for conveying millimeter wave signals. A conductive pocket may be mounted to the cover. The pocket may include a conductive rear wall and conductive sidewalls that extend from a periphery of the rear wall to the cover. The array may be mounted to the rear wall and may convey signals through the cover. The sidewalls may extend from the cover at non-zero angles with respect to the normal axis of the cover. The shape of the pocket and the cover may be selected so that the pocket is non-resonant at frequencies handled by the array, to mitigate destructive interference within the pocket, to block surface waves from propagating along the cover, and to tweak the radiation pattern of the array to exhibit a desired shape and directionality.

Abstract: An electronic device may include a substrate and a conductive layer on the substrate. The conductive layer may be patterned to form a first region and a second region that surrounds and defines the shape of the first region. The first region may be formed from a continuous portion of the conductive layer. The second region may include a grid of openings that divides the conductive layer into an array of patches. The first region may form an antenna resonating element for an antenna. The second region may block antenna currents from the antenna resonating element and may be transparent to radio-frequency electromagnetic waves. The openings may have a width that is too narrow to be discerned by the human eye. This may configure the first and second regions to appear as a single continuous conductive layer despite the fact that an antenna resonating element is formed therein.

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 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 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 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 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 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 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: A fracture interrogation system includes an antenna adapted for placement in a subterranean wellbore and a plurality of pseudoparticles adapted for distribution with a proppant material into hydraulic fractures along the wellbore. The presence of the pseudoparticles in the hydraulic fractures is detectable by the antenna. The pseudoparticles can include a magnetoelastic resonator having a resonant frequency. An interrogation field excites the resonators at the resonant frequency for detection by the antenna. The same or a different antenna can act as the interrogation field source, and the system can be configured to operate in a talk-and-listen mode to better separate the response signal from the interrogation signal. Electromagnetic, mechanical, or acoustic impulses can be used to excite resonators of the pseudoparticles.

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 first and second opposing surfaces. The second surface may face 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 promote bending. 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 communicate with an external device and may include one or more phased antenna arrays that transmit and receive a beam of millimeter wave signals. Beam steering circuitry may be coupled to the phased antenna array and may be adjusted to steer a direction of the beam. Control circuitry may control the beam steering circuitry to sweep the beam of millimeter wave signals over multiple beam directions. The control circuitry may gather wireless performance data and may compare the wireless performance metric data at each beam direction in the sweep prior to gathering wireless performance metric data at other beam directions in the sweep. The first beam direction in the sweep may be selected based on an initial position of the external device and/or based on sensor data gathered by the control circuitry.

Abstract: An electronic device may have a display cover layer mounted to a metal housing. Electrical component layers such as a display layer, touch sensor layer, and near-field communications antenna layer may be mounted under the display cover layer. An antenna feed may have a positive feed terminal coupled to the electrical component layers and a ground feed terminal coupled to the metal housing. The electrical component layers may serve as an antenna resonating element for an antenna. The antenna may cover cellular telephone bands and may receive satellite navigation system signals. A system-in-package device may be mounted to the metal housing. A flexible printed circuit may extend between the electrical component layers and the system-in-package device. A mounting bracket for the system-in-package device may be provided with electrical isolation to enhance antenna performance in bands such as a satellite navigation system band.

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 be provided with wireless communications circuitry and control circuitry. The wireless communications circuitry may include centimeter wave and millimeter wave transceiver circuitry and a phased antenna array. The phased antenna array may transmit and receive wireless signals having a frequency higher than 10 GHz. Beam steering circuitry may be coupled to the phased antenna array and may be adjusted to steer the wireless signals to communicate with external equipment. Sensor circuitry in the electronic device may gather sensor data. The control circuitry may use the gathered sensor data to determine a polarization mismatch between the electronic device and the external equipment (e.g., between a signal transmitting device and a signal receiving equipment or vice versa). To mitigate the polarization mismatch data loss, the control circuitry may adjust the polarization settings associated with antennas of the electronic device.