Abstract: An electronic device has antennas formed from cavity antenna structures. The electronic device may have a metal housing. The metal housing may have an upper housing in which a component such as a display is mounted and a lower housing in which a component such as a keyboard is mounted. Hinges may be used to mount the upper housing to the lower housing for rotation about a rotational axis. Cavity antennas may be formed in a clutch barrel region located between the hinges and running along the rotational axis. A flexible printed circuit may be formed between the cavity antennas. Each cavity antenna may have a first end that is adjacent to one of the hinges and a second end that is adjacent to the flexible printed circuit. Cavity walls for the cavity antennas may be formed from metal housing structures such as metal portions of the lower housing.

Abstract: An electronic device has antennas formed from cavity antenna structures. The electronic device may have a metal housing. The metal housing may have an upper housing in which a component such as a display is mounted and a lower housing in which a component such as a keyboard is mounted. Hinges may be used to mount the upper housing to the lower housing for rotation about a rotational axis. Cavity antennas may be formed in a clutch barrel region located between the hinges and running along the rotational axis. A flexible printed circuit may be formed between the cavity antennas. Each cavity antenna may have a first end that is adjacent to one of the hinges and a second end that is adjacent to the flexible printed circuit. Cavity walls for the cavity antennas may be formed from metal housing structures such as metal portions of the lower housing.

Abstract: An electronic device may be provided with slot antennas. A slot antenna may be formed from metal structures that have a dielectric gap defining an antenna slot. The metal structures may include multiple metal layers that overlap a plastic antenna window and that serve as capacitive electrodes in a capacitive proximity sensor. The metal structures may also include a metal electronic device housing. The metal electronic device housing and the metal layers may be formed on opposing sides of the antenna slot. The metal layers may have a notch that locally widens the antenna slot at an open end of the antenna slot. One of the metal layers may be shorted to the metal electronic device housing at an opposing closed end of the antenna slot. The antenna slot may be indirectly fed using a near-field-coupled antenna feed structure such as a metal patch that overlaps the antenna slot.

Abstract: An electronic device may include an adjustable power supply, at least one antenna, and associated antenna tuning circuitry. The antenna tuning circuitry may be an integral part of the antenna and may include a control circuit and at least one tunable element. The tunable element may include radio-frequency switches, continuously/semi-continuously adjustable components such as tunable resistors, inductors, and capacitors, and other load circuits that provide desired impedance characteristics. The power supply may provide power supply voltage signals to the antenna tuning circuitry via inductive coupling. The power supply voltage signals may be modulated according to a predetermined lookup table during device startup so that the control circuit is configured to generate desired control signals. These control signals adjust the tunable element so that the antenna can support wireless operation in desired frequency bands.

Abstract: An electronic device has antennas formed from cavity antenna structures. The electronic device may have a metal housing. The metal housing may have an upper housing in which a component such as a display is mounted and a lower housing in which a component such as a keyboard is mounted. Hinges may be used to mount the upper housing to the lower housing for rotation about a rotational axis. Cavity antennas may be formed in a clutch barrel region located between the hinges and running along the rotational axis. A flexible printed circuit may be formed between the cavity antennas. Each cavity antenna may have a first end that is adjacent to one of the hinges and a second end that is adjacent to the flexible printed circuit. Cavity walls for the cavity antennas may be formed from metal housing structures such as metal portions of the lower housing.

Abstract: An electronic device may have a housing such as a metal housing. A display may be mounted in the metal housing. Antenna structures may be mounted in the housing under an inactive peripheral portion of the display. Integrated circuits and other electrical components may be mounted in the housing under an active central portion of the display. Shielding structures may be configured to form a wall that extends between the display and the metal housing. The shielding structures may include a sheet of conductive fabric that is shorted to the metal housing and metal chassis structures in the display. The shielding structures may also include a tube of conductive fabric that is capacitively coupled to ground traces in a touch sensor panel. The conductive fabric tube and the sheet of conductive fabric may be shorted to each other using conductive adhesive.

Abstract: An electronic device such as a computer monitor is provided that has an antenna that supports near field communications. The electronic device may have a housing with conductive housing surfaces. A display may be mounted in the housing. The conductive housing surfaces may contain a dielectric-filled hole. The antenna may have a substrate and one or more loops of conductive traces. The loops may exhibit mirror symmetry. The loops may overlap the display and the conductive housing surface. The loops may surround an inner loop-free portion of the antenna. The loop-free portion of the antenna may overlap the hole. Ferrite layers may be interposed between the loops of the antenna that overlap the display and the loops of the antenna that overlap the conductive housing.

Abstract: An electronic device may be provided with a satellite positioning system slot antenna. The slot antenna may include a slot in a metal housing. The slot may be directly fed or indirectly fed. In indirectly fed configurations, the antenna may include a near-field-coupled antenna feed structure that is near-field coupled to the slot. The near-field-coupled antenna feed structure may be formed from a planar metal structure. The planar metal structure may be a metal patch that overlaps the slot and that has a leg that protrudes towards the metal housing. A positive antenna feed terminal may be coupled to the leg and a ground antenna feed terminal may be coupled to the metal housing.

Abstract: An electronic device may have a conductive housing with an antenna window. A display cover layer may be mounted on the front face of the device. Antenna and proximity sensor structures may include a dielectric support structure with a notch. The antenna window may have a protruding portion that extends into the notch between the display cover layer and the antenna and proximity sensor structures. The antenna and proximity sensor structures may have an antenna feed that is coupled to a first conductive layer by a high pass circuit and capacitive proximity sensor circuitry that is coupled to the first conductive layer and a parallel second conductive layer by a low pass circuit. The first conductive layer may be formed from a metal coating on the support structure. The second conductive layer may be formed from patterned metal traces in a flexible printed circuit.

Abstract: An electronic device may have an antenna for providing coverage in wireless communications bands of interest such as a low frequency communications band, a middle frequency communications band, and a high frequency communications band. Slot structures in the antenna that might reduce efficiency in the high frequency communications band may be avoided by capacitively loading the antenna and omitting meandering paths in the antenna. A capacitor may be coupled between an antenna ground formed from a metal housing structure and an antenna resonating element having a curved shape that conforms to the shape of the edge of the electronic device. The capacitor may have interdigitated fingers and may be adjustable to tune the antenna. The antenna may transmit and receive radio-frequency signals through a display cover layer in a display and a dielectric antenna window portion of the housing.

Abstract: An electronic device may have a conductive housing with an antenna window. Antenna structures may be mounted adjacent to the antenna window. The antenna structures may have a dielectric carrier. Patterned metal antenna traces may be formed on the surface of the dielectric carrier. A proximity sensor may be formed from a flexible printed circuit mounted on the dielectric carrier. The flexible printed circuit may have a tail that contains a transmission line for feeding the antenna structures. The transmission line may include a positive signal conductor that is maintained at a desired distance from the conductive housing using a polymer sheet. A portion of the antenna structures may protrude between a microphone and a camera module. Plastic camera module housing structures may have an inner surface coated with a shielding metal. A U-shaped conductive fabric layer may be used as a grounding structure.

Abstract: An electronic device may be provided with a conductive housing. An antenna window structure may be formed in an opening in the housing. The antenna window structure may have an antenna support structure that is attached to the conductive housing and that supports antenna structures. An antenna window cap may be mounted in the opening and attached to the antenna support structure with liquid adhesive. Alignment structures may be provided in the antenna support structure. An antenna support plate with mating alignment structures may be used in attaching the antenna structures to the antenna support structures. Metal shielding structures may be used to provide electromagnetic shielding. A shielding wall may be formed from a sheet metal structure supported by a plastic support structure. A flexible metal shielding foil layer may be welded to the shielding wall using a sacrificial plate.

Abstract: An electronic device may have a conductive housing with an antenna window. A display cover layer may be mounted on the front face of the device. Antenna and proximity sensor structures may include a dielectric support structure with a notch. The antenna window may have a protruding portion that extends into the notch between the display cover layer and the antenna and proximity sensor structures. The antenna and proximity sensor structures may have an antenna feed that is coupled to a first conductive layer by a high pass circuit and capacitive proximity sensor circuitry that is coupled to the first conductive layer and a parallel second conductive layer by a low pass circuit. The first conductive layer may be formed from a metal coating on the support structure. The second conductive layer may be formed from patterned metal traces in a flexible printed circuit.

Abstract: Electronic devices may be provided with antennas. An antenna may be formed from conductive antenna structures that include a frequency-dependent distributed capacitor. The antenna may include an antenna ground and an antenna resonating element that are separated by a gap. A low pass filter circuit may bridge the gap. The antenna resonating element may have antenna resonating element conductive structures that serve as first and second electrodes for the distributed capacitor. The second electrode may have first and second conductive elements coupled by a filter. The filter may be a low pass filter implemented using an inductor. The inductor may have a first terminal coupled to the first conductive element and a second terminal coupled to the second conductive element. A first antenna feed terminal may be coupled to the first conductive element and a second antenna feed terminal may be coupled to the antenna ground.

Abstract: An electronic device may include an adjustable power supply, at least one antenna, and associated antenna tuning circuitry. The antenna tuning circuitry may be an integral part of the antenna and may include a control circuit and at least one tunable element. The tunable element may include radio-frequency switches, continuously/semi-continuously adjustable components such as tunable resistors, inductors, and capacitors, and other load circuits that provide desired impedance characteristics. The power supply may provide power supply voltage signals to the antenna tuning circuitry via inductive coupling. The power supply voltage signals may be modulated according to a predetermined lookup table during device startup so that the control circuit is configured to generate desired control signals. These control signals adjust the tunable element so that the antenna can support wireless operation in desired frequency bands.

Abstract: An electronic device may include balance-fed antenna structures that do not have direct paths to ground. The antenna structures may serve as a Global Positioning System (GPS) antenna and may have a dipole structure having a first and second antenna resonating element arms. The antenna structures may include a conductive path that conveys antenna signals between a first feed terminal on the first antenna resonating element arm and a transmission line. The conductive path may overlap with the second antenna resonating element arm such that current flow through the conductive path induces corresponding current flow in the second antenna resonating element arm. The antenna structures may include an impedance matching short-circuit stub path that couples the first antenna resonating element arm to the second antenna resonating element arm. Choke inductors may be used to help block indirect paths from the antenna structures to ground through adjacent circuitry.

Abstract: An electronic device may be provided with a primary antenna that is used for transmitting and receiving signals and a secondary antenna that is used for receiving signals. The primary and secondary antennas may be used together in a diversity arrangement when receiving signals. The electronic device may have a transceiver. A phase shifter may be interposed between the transceiver and the secondary antenna. Control circuitry may select a communications band of interest for transmitting signals with the primary antenna. The control circuitry can adjust the phase shifter in real time based on which communications band of interest has been selected for transmission with the primary antenna. The phase shifter may impose a phase shift on signals carried between the secondary antenna and the transceiver that ensures that primary antenna efficiency degradation associated with the presence of the secondary antenna in the vicinity of the primary antenna is avoided.

Abstract: An electronic device may have a cavity antenna. The cavity antenna may have a logo-shaped dielectric window. An antenna resonating element for the cavity antenna may be formed from conductive traces on a printed circuit board. An antenna resonating element may be formed from the traces. The antenna resonating element may be mounted on an antenna support structure. A conductive cavity structure for the cavity antenna may have a planar lip that is mounted flush with an interior surface of a conductive housing wall. The cavity structure may have more than one depth. Shallower planar portions of the cavity structure may lie in a plane. The antenna resonating element may be located between the plane of the shallow cavity walls and an external surface of the conductive housing wall.

Abstract: Electronic devices may be provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and antennas. An antenna may have an antenna ground that is configured to form a cavity for the antenna. The antenna ground may be formed on a support structure. The antenna ground may have an opening. The support structure may have a planar surface on which the opening is formed. A folded monopole antenna resonating element and an L-shaped conductive antenna element may be formed in the opening and may be capacitively coupled. The folded monopole antenna resonating element may have an end at which a positive antenna feed terminal is formed. A ground antenna feed terminal may be formed on the antenna ground. A segment of the antenna ground may extend between the ground antenna feed terminal and an end of the L-shaped conductive antenna element.

Abstract: Antennas are provided for electronic devices such as portable computers. An electronic device may have a housing in which an antenna is mounted. The housing may be formed of conductive materials. A dielectric 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. A proximity sensor adjacent to the dielectric window may be used in detecting external objects. The antenna may have an antenna resonating element that is mounted against an inner surface of a display cover glass layer. The antenna resonating element may be mounted to an upper surface of a plastic carrier. An electromagnetic shield may be mounted on a lower surface of the plastic carrier above the proximity sensor.