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. The slot of each slot antenna resonating element may divide the ground plane into first and second portions. A return path and feed may be coupled in parallel between the planar metal member and the first portion of the ground plane. Tunable components such as tunable inductors may be used to tune the hybrid antennas. A tunable inductor may bridge the slot in hybrid antenna, may be coupled between the planar metal member of the planar inverted-F antenna resonating element and the ground plane, or multiple tunable inductors may bridge the slot on opposing sides of the planar inverted-F antenna resonating element.

Abstract: A removable case may have a body that is configured to receive an electronic device. The case may be coupled to the electronic device using wired and wireless paths. The case may include circuitry that receives wireless power from external equipment. The circuitry that receives the wireless power may receive wireless power at microwave frequencies. Received power may be supplied to the electronic device through wired and wireless paths. The removable case may also include circuitry that wirelessly communicates with external equipment. An array of antennas may be used to support beam steering. The array of antennas may support wireless communications in millimeter wave communications bands such as a communications band at 60 GHz or other extremely high frequency communications bands. The case and electronic device may have respective intermediate frequency antenna structures to allow intermediate frequency signals to be wirelessly conveyed between the case and device.

Abstract: An electronic device may be provided with wireless circuitry. The wireless circuitry may include one or more antennas. The antennas may include millimeter wave antenna arrays formed from arrays of patch antennas, dipole antennas or other millimeter wave antennas on millimeter wave antenna array substrates. Circuitry such as upconverter and downconverter circuitry may be mounted on the substrates. The upconverter and downconverter may be coupled to wireless communications circuitry such as a baseband processor circuit using an intermediate frequency signal path. The electronic device may have opposing front and rear faces. A display may cover the front face. A rear housing wall may cover the rear face. A metal midplate may be interposed between the display and rear housing wall. Millimeter wave antenna arrays may transmit and receive antenna signals through the rear housing wall.

Abstract: An electronic device may be provided with an antenna and transceiver circuitry such as millimeter wave transceiver circuitry. The antenna may include an antenna ground and a resonating element. The resonating element may include a cross-shaped patch having arms extending along different longitudinal axes, conductive landing pads interposed between the cross-shaped patch and the antenna ground, and vertical conductive legs extending between each of the arms and corresponding landing pads. The antenna may be fed using a first antenna feed coupled between a first of the landing pads and the antenna ground and a second antenna feed coupled between a second of the landing pads and the antenna ground. The landing pads, antenna ground, and cross-shaped patch may be formed from conductive traces on different layers of a dielectric substrate.

Abstract: An electronic device may be provided with wireless circuitry, a conductive housing, and a display. The display may have an active area that displays image data and an inactive area that does not display image data. The active area may completely surround the inactive area at a front face of the device. A speaker port may be aligned with the inactive area and may emit sound through the inactive area. The wireless circuitry may include first and second antenna arrays. The first array may be configured to transmit and receive wireless signals at frequencies between 10 GHz and 300 GHz through the inactive area of the display. The second array may be configured to transmit and receive wireless signals at frequencies between 10 GHz and 300 GHz through a slot in a rear wall of the conductive housing. Control circuitry may perform beam steering using the first and second arrays.

Abstract: An electronic device may include a housing and four antennas at respective corners of the housing. Cellular telephone transceiver circuitry may concurrently convey signals at one or more of the same frequencies over one or more of the four antennas using a multiple-input multiple-output (MIMO) scheme. In order to isolate adjacent antennas, dielectric-filled openings may be formed in conductive walls of the housing to divide the walls into segments that are used to form resonating element arms for the antennas. If desired, first and second antennas may include resonating element arms formed from a wall without any gaps. The first and second antennas may include adjacent return paths. A magnetic field associated with currents for the first antenna may cancel out with a magnetic field associated with currents for the second antenna at the adjacent return paths, thereby serving to electromagnetically isolate the first and second antennas.

Abstract: An electronic device may include antennas, a ground, and a housing. First and second gaps in the housing may define a segment that forms a resonating element for a first antenna. First, second, third, and fourth antenna feeds may be coupled between the segment and ground. Control circuitry may control adjustable components to place the device in first, second, third, or fourth modes. In the first and second modes, the first and fourth feeds convey signals at the same frequency using a multiple-input and multiple-output scheme while the second and third feeds are inactive. In the third mode, the second feed is active and the first, third, and fourth feeds are inactive. In the fourth mode, the third feed is active and the first, second, and fourth antenna feeds are inactive. Isolating return paths may be coupled between the segment and ground in the first and second modes.

Abstract: An electronic device may be provided with millimeter wave transceiver circuitry and an antenna having a ground and a resonating element. The resonating element may include first and second patches symmetrically distributed about an axis. The antenna may be fed using an antenna feed having a first feed terminal coupled to both the first and second patches and a second feed terminal coupled to the ground. The first feed terminal may be coupled to the first patch at a side closest to the second patch and may be coupled to the second patch at a side closest to the first patch. The first and second patches may be shorted to the ground if desired. Antenna currents on the first patch may be 180 degrees out of phase with antenna currents on the second patch. The antenna may be arranged in an array of antennas with different polarizations.

Abstract: An electronic device may be provided with control signal generation circuitry that generates a differential pair of control signals, power supply circuitry that generates a bias voltage, and an antenna having a tuning circuit. First switching circuitry may be coupled to the power supply circuitry and the control signal generation circuitry. Second switching circuitry may be coupled to the tuning circuit. A pair of control lines may be coupled between the first and second switching circuitry. In a first switching mode, the power supply circuitry may transmit the bias voltage to the tuning circuit over one of the control lines. The bias voltage may charge storage circuitry coupled to the tuning circuit. In a second switching mode, the control signal generation circuitry may transmit the differential pair of control signals to the tuning circuit. The tuning circuit may be powered by the storage circuitry in the second switching mode.

Abstract: An electronic device may include a millimeter wave transceiver, a first antenna having a first resonating element at a first side of a substrate, and a second antenna having a second resonating element at a second side of the substrate. A first coplanar waveguide may convey millimeter wave signals between the transceiver and the first resonating element and a second coplanar waveguide may convey millimeter wave signals between the transceiver and the second resonating element. The first coplanar waveguide may be coupled to the first resonating element through the second coplanar waveguide. The second coplanar waveguide may be coupled to the second resonating element through the first coplanar waveguide. Ground conductors in the coplanar waveguides may form antenna ground planes for the first and second antennas while serving to maximize electromagnetic decoupling between the coplanar waveguides and thus isolation between the ports of the transceiver.

Abstract: An electronic device may be provided with wireless circuitry that includes one or more antennas and a transceiver. An integrated circuit may be coupled between the transceiver and the antenna and may include multiple tunable components such that tune the response of the antenna. The control signals may be generated by a tuning controller external to the integrated circuit. Shared control interface circuitry may be formed on the integrated circuit for interfacing between the tuning controller and each of the tunable components on the integrated circuit. The control interface circuitry may include a conductive path and decoupling circuitry that routes the control signals to corresponding control inputs on each of the tunable components. Sharing the control interface circuitry between each tunable component on the integrated circuit may minimize the space required on the integrated circuit for controlling the response of the antenna.

Abstract: An electronic device may be provided with control signal generation circuitry that generates a differential pair of control signals, power supply circuitry that generates a bias voltage, and an antenna having a tuning circuit. First switching circuitry may be coupled to the power supply circuitry and the control signal generation circuitry. Second switching circuitry may be coupled to the tuning circuit. A pair of control lines may be coupled between the first and second switching circuitry. In a first switching mode, the power supply circuitry may transmit the bias voltage to the tuning circuit over one of the control lines. The bias voltage may charge storage circuitry coupled to the tuning circuit. In a second switching mode, the control signal generation circuitry may transmit the differential pair of control signals to the tuning circuit. The tuning circuit may be powered by the storage circuitry in the second switching mode.

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 be provided with wireless circuitry including first and second patch antennas. The first patch antenna may include a first resonating element formed over a ground plane. The second patch antenna may include a second resonating element over the first resonating element. A cross-shaped parasitic element may be formed over the second resonating element. First and second feed terminals may be coupled to the second resonating element. An opening may be formed in the first resonating element. First and second transmission lines may be coupled to the first and second feed terminals through the opening. The cross-shaped parasitic element may include arms that overlap the first and second feed terminals. The first resonating element may cover first frequencies between 10 GHz and 300 GHz and the second resonating element may cover second frequencies that are higher than the first frequencies.

Abstract: An electronic device may include a millimeter wave antenna having a ground plane, resonating element, feed, and parasitic element. The resonating element may include first, second, and third layer of traces that are shorted together. The second traces may be interposed between the first and third traces and the third traces may be interposed between the second traces and the parasitic. The third traces may have a width that is less than the widths of the second and third traces. The third traces and the parasitic may define a constrained volume having an associated cavity resonance that lies outside of a frequency band of interest. If desired, the resonating element may include a single layer of conductive traces having a grid of openings that disrupt impedance in a transverse direction, thereby mitigating the trapping of energy within the frequency band of interest between the resonating element and the parasitic.

Abstract: An electronic device may be provided with wireless circuitry that includes a phased antenna array. The array may include first, second, and third rings of antennas on a dielectric substrate that cover respective first, second, and third communications bands greater than 10 GHz. The second ring of antennas may surround the first ring of antennas. The third ring of antennas may be formed over the second ring of antennas. Parasitic elements may be formed over the first ring of antennas to broaden the bandwidth of the first ring of antennas. Beam steering circuitry may be coupled to the rings of antennas. Control circuitry may control the beam steering circuitry to steer a beam of wireless signals in one or more of the first, second, and third communications bands. The array may exhibit relatively uniform antenna gain regardless of the direction in which the beam is steered.

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 include an antenna having a resonating element, an antenna ground, and a feed. First and second tunable components may be coupled to the resonating element. Adjustable matching circuitry may be coupled to the feed. Control circuitry may use the first tunable component to tune a midband antenna resonance when sensor circuitry identifies that the device is being held in a right hand and may use the second tunable component to tune the midband resonance when the sensor circuitry identifies that the device is being held in a left hand. For tuning a low band resonance, the control circuitry may place the antenna in different tuning states by sequentially adjusting a selected one of the matching circuitry and the tunable components, potentially reverting to a previous tuning state at each step in the sequence. This may ensure that antenna efficiency is satisfactory regardless of antenna loading conditions.

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: 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.