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 has wireless communications circuitry including an adjustable antenna system coupled to a radio-frequency transceiver. The adjustable antenna system may include one or more adjustable electrical components that are controlled by storage and processing circuitry in the electronic device. The adjustable electrical components may include switches and components that can be adjusted between numerous different states. The adjustable electrical components may be coupled between antenna system components such as transmission line elements, matching network elements, antenna elements and antenna feeds. By adjusting the adjustable electrical components, the storage and processing circuitry can tune the adjustable antenna system to ensure that the adjustable antenna system covers communications bands of interest.

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 formed from printed circuit board Yagi antennas or other antennas. A millimeter wave transceiver may use the antennas to transmit and receive wireless signals. The antennas may be mounted at the corners of an electronic device housing or elsewhere in an electronic device. An electronic device housing may be formed from metal and may have an opening filled with dielectric. The antennas may be aligned with portions of the dielectric. Printed circuit board antennas may have reflectors, radiators, and directors. The reflectors, radiators, and directors may be arranged to align radiation patterns for the antennas with the plastic-filled slots or other dielectric regions in the metal housing.

Abstract: A housing for a personal electronic device is described herein. The housing may include at least one modular subassembly configured to be arranged within an internal cavity of the housing. The at least one modular subassembly is aligned with a feature external to the housing, is affixed to an interior surface of the internal cavity, and is configured to function both as an antenna and as an internal support member of the housing.

Abstract: Systems, methods, and devices are provided to estimate angle of arrival of wireless signals. An electronic device may include two or more antennas that receive a wireless transmission. The wireless transmission includes a first frequency signal at a first frequency and a second frequency signal at a second frequency. The electronic device includes angle of arrival logic that may determine one or more angles of arrival of the wireless transmission to the electronic device using phase difference on arrival based on each of the first and second frequency signals.

Abstract: A housing for a personal electronic device is described herein. The housing may include at least one modular subassembly configured to be arranged within an internal cavity of the housing. The at least one modular subassembly is aligned with a feature external to the housing, is affixed to an interior surface of the internal cavity, and is configured to function both as an antenna and as an internal support member of the housing. A hybrid antenna is also described herein. The hybrid antenna can include first and second flexible members capable of facilitating wireless communication, where the first and second flexible members are affixed to one another via a metal member.

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: An electronic device may include wireless circuitry that is configured to transmit wireless signals during operation. A maximum transmit power level may be established that serves as a cap on how much power is transmitted from the electronic device. Adjustments may be made to the maximum transmit power level in real time based on sensor signals and other information on the operating state of the electronic device. The sensor signals may include motion signals from an accelerometer. The sensor signals may also include ultrasonic sound detected by a microphone. Device orientation data may be used by the device to select whether to measure the ultrasonic sound using a front facing or rear facing microphone. Maximum transmit power level may also be adjusted based on whether or not sound is playing through an ear speaker in the device.

Abstract: An electronic device may have wireless circuitry with antennas. An antenna resonating element arm for an antenna may be formed from conductive housing structures running along the edges of a device. The antenna may have a pair of switchable return paths that bridge a slot between the antenna resonating element and an antenna ground. An adjustable component and a feed may be coupled in parallel across the slot. The adjustable component may switch a capacitor into use or out of use and the return paths may be selectively opened and closed to compensate for antenna loading due to the presence of external objects near the electronic device.

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 a printed circuit. The printed circuit may be a stacked printed circuit including multiple stacked substrates. Metal traces may form an array of patch antennas, Yagi antennas, and other antennas. Antenna signals associated with the antennas may pass through an inactive area in a display and through a dielectric-filled slot in a metal housing for the electronic device. Waveguide structures may be used to guide antenna signals within interior portions of the electronic device.

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: 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: This disclosure relates to systems, methods, and apparatus for limiting or throttling an activity of an accessory device communicatively coupled to a computing device. The activity of the accessory device is limited or throttled in order to reduce electromagnetic interference and improve signal quality of a wireless communication in which the computing device is participating. In some embodiments, a decision to throttle can be based on battery charge level of the computing device. For example, in some embodiments, the accessory device is an accessory battery charger configured to provide power to the computing device when a power outlet is not immediately available. If the signal quality of a phone call from the computing device is diminished or the user is in an area of low signal coverage, the accessory battery charger can be limited or throttled in order to prevent interference between the accessory battery charger and computing device.

Abstract: An electronic device has wireless communications circuitry including an adjustable antenna system coupled to a radio-frequency transceiver. The adjustable antenna system may include one or more adjustable electrical components that are controlled by storage and processing circuitry in the electronic device. The adjustable electrical components may include switches and components that can be adjusted between numerous different states. The adjustable electrical components may be coupled between antenna system components such as transmission line elements, matching network elements, antenna elements and antenna feeds. By adjusting the adjustable electrical components, the storage and processing circuitry can tune the adjustable antenna system to ensure that the adjustable antenna system covers communications bands of interest.

Abstract: A host device is configured to increase the power output by an internal amplifier of its wireless chipset in response to requests from a remote device. Once the internal amplifier has reached its maximum power, further requests for power increases from the remove device do not similarly lead to automatic power increases being delivered by a external amplifier of the host device. Rather, the host device determines the strength of the link between it and the remote device. If the signal strength is too low, it is an indication that the signal power output by the remote device may not be sufficient to maintain the link and that any further increases in signal power by the host device will have little or no effect on the link. However, if the signal strength from the remote device is sufficient, the host device determines an error rate between it and the remote device. If the error rate is sufficiently low to maintain the link, then the host device will not further increase its signal output power.

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 a printed circuit. The printed circuit may be a stacked printed circuit including multiple stacked substrates. Metal traces may form an array of patch antennas, Yagi antennas, and other antennas. Antenna signals associated with the antennas may pass through an inactive area in a display and through a dielectric-filled slot in a metal housing for the electronic device. Waveguide structures may be used to guide antenna signals within interior portions of the electronic device.

Abstract: An electronic device may have wireless circuitry with antennas. An antenna resonating element arm for an antenna may be formed from conductive housing structures running along the edges of a device. The antenna may have a pair of switchable return paths that bridge a slot between the antenna resonating element and an antenna ground. An adjustable component and a feed may be coupled in parallel across the slot. The adjustable component may switch a capacitor into use or out of use and the return paths may be selectively opened and closed to compensate for antenna loading due to the presence of external objects near the electronic device.

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 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.

Abstract: This invention is directed to an electronic device with an embedded authentication system for restricting access to device resources. The authentication system may include one or more sensors operative to detect biometric information of a user. The sensors may be positioned in the device such that the sensors may detect appropriate biometric information as the user operates the device, without requiring the user to perform a step for providing the biometric information (e.g., embedding a fingerprint sensor in an input mechanism instead of providing a fingerprint sensor in a separate part of the device housing). In some embodiments, the authentication system may be operative to detect a visual or temporal pattern of inputs to authenticate a user. In response to authenticating, a user may access restricted files, applications (e.g., applications purchased by the user), or settings (e.g., application settings such as contacts or saved game profile).