Abstract:
Electronic devices are provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and antenna structures. The antenna structures may include antennas such as inverted-F antennas that contain antenna resonating elements and antenna ground elements. Antenna resonating elements may be formed from patterned conductive traces on substrates such as flex circuit substrates. Antenna ground elements may be formed from conductive device structures such as metal housing walls. Support and biasing structures such as dielectric support members and layer of foam may be used to support and bias antenna resonating elements against planar device structures. The planar device structures against which the antenna resonating elements are biased may be planar dielectric members such as transparent layers of display cover glass or other planar structures. Adhesive may be interposed between the planar structures and the antenna resonating elements.
Abstract:
An electronic device may be provided with antenna structures. Proximity sensors and other sensors may be used in determining how the electronic device is being operated. Wireless circuitry such as a radio-frequency transmitter associated with a cellular telephone communications band, a wireless local area network band, or other communications band may be used in transmitting radio-frequency signals through the antenna structures at a transmit power. Control circuitry may adjust the wireless circuitry to ensure that the transmit power is capped at a maximum transmit power. The maximum transmit power may be adjusted dynamically by the control circuitry based on data from the proximity sensors, data from a magnetic sensor that detects whether a cover is present on the device, a connector sensor that detects whether the device is coupled to a dock or other accessory, and other sensors.
Abstract:
An electronic device may have a housing in which an antenna is mounted. An antenna window may be mounted in the housing to allow radio-frequency signals to be transmitted from the antenna and to allow the antenna to receive radio-frequency signals. Near-field radiation limits may be satisfied by reducing transmit power when an external object is detected in the vicinity of the dielectric antenna window and the antenna. A capacitive proximity sensor may be used in detecting external objects in the vicinity of the antenna. The proximity sensor may have conductive layers separated by a dielectric. A capacitance-to-digital converter may be coupled to the proximity sensor by inductors. The capacitive proximity sensor may be interposed between an antenna resonating element and the antenna window. The capacitive proximity sensor may serve as a parasitic antenna resonating element and may be coupled to the housing by a capacitor.
Abstract:
An electronic device may have an antenna for providing coverage in wireless communications bands of interest such as a low frequency communications band and a high frequency communications band. The antenna may have an antenna ground and an antenna resonating element. The antenna resonating element may have a high band arm that contributes to a first high band resonance in the high band and may have a low band arm that exhibits a low band resonance in the low band. A passive filter that is coupled between first and second portions of the antenna resonating element may be configured to exhibit a short circuit impedance associated with a bypass path that allows the antenna resonating element to contribute to a second high band resonance in the high band. A tunable inductor coupled to the antenna resonating element may be used to tune the low band resonance.
Abstract:
An electronic device such as a head-mounted display device may include an antenna that radiates through a cover. The antenna may have an antenna resonating element layered onto the cover and having a three-dimensional curvature. The antenna resonating element may have an antenna ground. A pressure-activated connector may electrically couple the antenna resonating element to the antenna ground. If desired, the pressure-activated connector may lock the antenna resonating element to the antenna ground. The pressure-activated connector may include a metal finger, a metal spring, a metal ball, a curling metal receptacle, a dimple, a metal screw, a screw receptacle, metal burs, and/or rotational locking structures. The pressure-activated connector may form a robust mechanical connection between the first and second conductors despite the curvature of the antenna resonating element, which minimizes electrical discontinuities that can otherwise deteriorate antenna performance.
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:
A head-mounted device may have a head-mounted housing. The housing may include a frame with left and right openings that receive respective left and right optical modules that present images to a user's eyes. Each optical module may have a lens and display that presents an image through the lens. Camera support members may be coupled to respective left and right peripheral portions of the frame. Each camera support member may have openings configured to receive cameras. Antennas may be formed on a camera support member. The antennas may have metal traces on a surface of the camera support member, may have conductive structures embedded within the camera support member, and/or may have patterned metal traces on printed circuits attached to or embedded in the camera support member. The cameras may operate through portions of a display cover layer that covers an outwardly-facing display on the head-mounted housing.
Abstract:
A head-mounted device may have a head-mounted housing. A radar sensor may be mounted in the 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 forward-facing camera may capture real-world image content. The rear-facing displays may be used to display captured real-world image content merged with computer-generated image content. The forward-facing camera and the radar sensor may be mounted under inactive display borders of a forward-facing display. The radar sensor may have a horizontal array of patch antenna elements configured to form a phased antenna array. Communications circuitry in the head-mounted device may use the phased antenna array to transmit and receive wireless communications signals.
Abstract:
An electronic device may be provided with a phased antenna array on an antenna module. The array may include low band antennas and high band antennas that radiate at frequencies greater than 10 GHz. The module may include antenna layers, transmission line layers, and ground traces that separate the antenna layers from the transmission line layers. The low band antennas and the high band antennas may have radiators patterned onto the antenna layers. The radiators may be fed by transmission lines on the transmission line layers. The antenna layers may have a dielectric permittivity that is greater than the dielectric permittivity of the transmission line layers. This may serve to reduce the lateral footprint of the low band and high band antennas, which allows the antennas to be interleaved along a common linear axis in the phased antenna array, thereby minimizing the lateral footprint of the antenna module.
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.