Abstract: An electronic device may have components mounted in a housing. The device may include wireless transceiver circuitry and antenna structures. A display may be mounted in the housing. The display may have a cover layer having an inner surface with a recess. The recess may run along a peripheral edge of the cover layer. An antenna structure such as an inverted-F antenna resonating element may be formed from a metal trace on a dielectric antenna carrier. The resonating element may be mounted in the recess without adhesive. Conductive vias may pass through the dielectric carrier. Metal members with dimples may be soldered to a flexible printed circuit and may be used to ground metal traces on the carrier and the flexible printed circuit to the housing when the carrier is attached to the housing with fasteners.

Abstract: Electronic devices may be provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and antenna structures. The antenna structures may include conductive housing structures such as a peripheral conductive housing member. The antenna structures may be based on an inverted-F antenna resonating element or other types of antenna resonating element. An electronic device may have near field communications circuitry and non-near-field communications circuitry such as cellular telephone, satellite navigation system, or wireless local area network transceiver circuitry. Antenna structures may be configured to handle signals associated with the non-near-field communications circuitry. The antenna structures may also have portions that form a near field communications loop antenna for handling signals associated with the near field communications circuitry.

Abstract: A computer stylus may have an elongated body with a tip and an opposing end having components such as a connector and an antenna. Metal structures for the antenna may be supported using a molded plastic support with metal traces or may be formed using flexible printed circuits or other structures. Metal and plastic tubes may be used in forming the body of the stylus. A metal tube may have an opening in which an antenna is mounted. A plastic tube may serve as an outer housing for the stylus and may cover the metal tube and the opening in which the antenna is mounted. A transmission line such as a cable may be coupled to an antenna feed. The cable may pass through an opening in the metal tube and may be covered using a strip of conductive foam.

Abstract: An electronic device may have wireless circuitry with antennas. An antenna resonating element arm for an antenna may be formed from peripheral conductive structures running along the edges of a device housing. Elongated conductive members may longitudinally divide openings between the peripheral conductive housing structures and the ground. The elongated conductive members may extend from an internal ground to outer ends of the elongated conductive members that are located adjacent to the gaps. Transmission lines may extend along the elongated conductive members to antenna feeds at the outer ends. The elongated conductive members may form open slots that serve as slot antenna resonating elements for the antenna.

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 may be provided with wireless circuitry. Control circuitry may be used to adjust the wireless circuitry. The wireless circuitry may include an antenna that is tuned using tunable components. The control circuitry may gather information on the current operating mode of the electronic device, sensor data from a proximity sensor, accelerometer, microphone, and other sensors, antenna impedance information for the antenna, and information on the use of connectors in the electronic device. Based on this gathered data, the control circuitry can adjust the tunable components to compensate for antenna detuning due to loading from nearby external objects, may adjust transmit power levels, and may make other wireless circuit adjustments.

Abstract: An electronic device may be provided with wireless circuitry. The wireless circuitry may include antennas. The antennas may include phased antenna arrays for handling millimeter wave signals. Antennas may be located in antenna signal paths. The antenna signal paths may include adjustable components such as adjustable filters, adjustable gain amplifiers, and adjustable phase shifters. Circuitry may be incorporated into an electronic device to facilitate wireless self-testing operations. Wireless self-testing may involve use of one antenna to transmit an over-the-air antenna test signal that is received by another antenna. The circuitry that facilitates the wireless self-testing operations may include couplers, adjustable switches for temporarily shorting antenna signal paths together, mixers for mixing down radio-frequency signals to allow digitization with analog-to-digital converters, and other circuitry for supporting self-testing operations.

Abstract: An electronic device may have a display in a housing with a metal wall. An antenna may have an antenna ground formed from the wall and an antenna resonating element. Transceiver circuitry may be coupled to an antenna feed that extends between the antenna resonating element and the antenna ground. A return path may extend between the antenna resonating element and the antenna ground in parallel with the feed. The antenna resonating element may have segments that are coupled by a frequency dependent filter. At a first frequency, the filter may have a low impedance so that the antenna resonating element has a first effectively length. At a second frequency that is greater than the first frequency, the filter may have a high impedance so that the antenna resonating element has a second effective length that is shorter than the first effective length.

Abstract: An accessory such as a wireless earbud may have an antenna for transmitting and receiving wireless signals. A housing for the earbud may have a main body portion and an extended portion that forms a stalk protruding from the main body portion. The earbud may have a speaker aligned with a speaker port in the main body portion. The antenna may have an elongated shape and may extend along the stalk. The stalk may have a plastic housing wall portion. The antenna may be formed from first and second metal traces on opposing sides of a printed circuit substrate. The first metal trace may form an antenna resonating element arm and may lie between the substrate and the plastic housing wall portion. The second metal trace may be a ground trace. A feed for the antenna may be located at a juncture between the main body portion and the stalk.

Abstract: Electronic devices may include antenna structures. The antenna structures may form an antenna having first and second feeds at different locations. Transceiver circuitry for transmitting and receiving radio-frequency antenna signals may be mounted on one end of a printed circuit board. Transmission line structures may be used to convey signals between an opposing end of the printed circuit board and the transceiver circuitry. The printed circuit board may be coupled to an antenna feed structure formed from a flexible printed circuit using solder connections. The flexible printed circuit may have a bend and may be screwed to conductive electronic device housing structures using one or more screws at one or more respective antenna feed terminals. Electrical components such as an amplifier circuit and filter circuitry may be mounted on the flexible printed circuit.

Abstract: An electronic device may be provided with wireless circuitry. The wireless circuitry may include one or more antennas. An antenna may have an antenna feed that is coupled to a radio-frequency transceiver with a transmission line. An impedance matching circuit may be coupled to the antenna feed to match the impedance of the transmission line and the antenna. The impedance matching circuit and tunable circuitry in the antenna may be formed using integrated circuits. Each integrated circuit may include switching circuitry that is used in switching components such as inductors and capacitors into use. Sensors such as temperature sensors, current and voltage sensors, power sensors, and impedance sensors may be integrated into the integrated circuits. Each integrated circuit may store settings for the switching circuitry and may include communications and control circuitry for communicating with external circuits and processing sensor data.

Abstract: An electronic device may be provided with wireless circuitry. The wireless circuitry may include an antenna. The electronic device may have a housing in which control circuitry and radio-frequency transceiver circuitry is mounted. The transceiver circuitry may be used to transmit and receive radio-frequency signals with the antenna. The housing may have a housing wall with a locally thinned portion aligned with the antenna. The antenna may have a sheet metal layer attached to a plastic cavity with a layer of adhesive. Recesses in a printed circuit may receive prongs formed from a sheet metal layer. The plastic carrier may have cavities separated by ribs. The sheet metal layer may form a planar inverted-F antenna resonating element, a ground plane, a return path between the resonating element and ground plane, and a feed path that extends along one of the ribs and into an opening in the printed circuit.

Abstract: An electronic device housing may have a base unit and a lid. Aligned antenna windows may be formed on opposing upper and lower surfaces of the base unit along a hinge. Antenna structures that are located between respective upper and lower antenna windows on the upper and lower surfaces may be based on a pair of antennas that are coupled to switching circuitry that can select which antenna to switch into use or may be based on an antenna having a position that may be adjusted relative to the upper and lower antenna windows using a mechanical coupling to the lid or using a positioner. A sensor such as a lid position sensor may monitor how the lid is positioned relative to the base unit. Information from the lid position sensor may be used in adjusting the antenna structures to optimize performance.

Abstract: An electronic device may be provided with wireless circuitry. The wireless circuitry may include antennas. The antennas may include phased antenna arrays for handling millimeter wave signals. Antennas may be located in antenna signal paths. The antenna signal paths may include adjustable components such as adjustable filters, adjustable gain amplifiers, and adjustable phase shifters. Circuitry may be incorporated into an electronic device to facilitate wireless self-testing operations. Wireless self-testing may involve use of one antenna to transmit an over-the-air antenna test signal that is received by another antenna. The circuitry that facilitates the wireless self-testing operations may include couplers, adjustable switches for temporarily shorting antenna signal paths together, mixers for mixing down radio-frequency signals to allow digitization with analog-to-digital converters, and other circuitry for supporting self-testing operations.

Abstract: An electronic device may be provided with wireless circuitry. The wireless circuitry may include one or more antennas. The antennas may include phased antenna arrays each of which includes multiple antenna elements. Phased antenna arrays may be mounted along edges of a housing for the electronic device, behind a dielectric window such as a dielectric logo window in the housing, in alignment with dielectric housing portions at corners of the housing, or elsewhere in the electronic device. A phased antenna array may include arrays of patch antenna elements on dielectric layers separated by a ground layer. A baseband processor may distribute wireless signals to the phased antenna arrays at intermediate frequencies over intermediate frequency signal paths. Transceiver circuits at the phased antenna arrays may include upconverters and downconverters coupled to the intermediate frequency signal paths.

Abstract: Electronic devices are provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and antenna structures. An inverted-F antenna may have first and second short circuit legs and a feed leg. The first and second short circuit legs and the feed leg may be connected to a folded antenna resonating element arm. The antenna resonating element arm and the first short circuit leg may be formed from portions of a conductive electronic device bezel. The folded antenna resonating element arm may have a bend. The bezel may have a gap that is located at the bend. Part of the folded resonating element arm may be formed from a conductive trace on a dielectric member. A spring may be used in connecting the conductive trace to the electronic device bezel portion of the antenna resonating element arm.

Abstract: A removable case may receive an electronic device. A male connector in the case may mate with a female connector in the device. A battery in the case may supply power to the device through the male connector. The electronic device may have an antenna formed from peripheral conductive housing structures and an antenna ground. The antenna may include a slot antenna resonating element. The case may have supplemental antenna structures such as a metal patch that overlaps an end of the slot antenna resonating element to retune the slot antenna resonating element to a desired operating frequency after being detuned by dielectric loading from the case. The supplemental antenna structures may overlap antennas of other types and may include tunable circuitry that is adjusted based on information received from the electronic device.

Abstract: An electronic device may be provided with an antenna. The antenna may have an antenna resonating element and an antenna ground. The antenna resonating element may be formed from peripheral conductive housing structures. An audio jack or other connector may be mounted in an opening in the peripheral conductive housing structures. The audio jack may overlap the antenna ground. Contacts in the audio jack may be coupled to an interference mitigation circuit. The interference mitigation circuit may include capacitors coupled to the ground and inductors coupled between the contacts and the capacitors. Radio-frequency signal blocking inductors may be coupled between the interference mitigation circuit and respective ports in an audio circuit.

Abstract: An electronic device may have wireless circuitry and components such as sensors. The electronic device may have a metal housing having first and second planar rear wall portions separated by a gap. Conductive structures may bridge the gap to electrically couple the first and second rear wall portions. The wireless circuitry may include a hybrid slot inverted-F antenna. The antenna may have an inverted-F antenna resonating element formed from peripheral housing structures that are separated from the second rear wall portion by an opening. The opening may form a C-shaped slot antenna resonating element for the antenna. The sensors may include a fingerprint sensor. The fingerprint sensor may be coupled to a button member in a button. The fingerprint sensor and other portions of the button may overlap the second planar rear wall portion to minimize interference with antenna operation.

Abstract: An electronic device may be provided with wireless circuitry. The wireless circuitry may include one or more dual-frequency dual-polarization patch antennas. Each patch antenna may have a patch antenna resonating element that lies in a plane and a ground that lies in a different parallel plane. The patch antenna resonating element may have a first feed located along a first central axis and a second feed located along a second central axis that is perpendicular to the first central axis. The patch antenna resonating element may be rectangular, may be oval, or may have other shapes. A shorting pin may be located at an intersecting point between the first and second axes. The patch antennas may be used in beam steering arrays. The patch antennas may be used for wireless power transfer at microwave frequencies or other frequencies and may be used to support millimeter wave communications.