Abstract: A radio frequency device has a multifunctional tuner that stores measurements of reflection coefficient parameter in a register. The radio frequency device also has a transceiver that has a transmitter. The transceiver may detect a transmitter signal from the transmitter to an antenna in an initial tuning state and then determine whether the transmitter signal is stable. In response to the transmitter signal being stable, the transceiver may measuring the reflection coefficient parameters at the multifunctional tuner. Furthermore, the radio frequency device has a baseband controller that has a memory to store instructions and a processor to execute the instructions. The instructions cause the processor to determine an antenna impedance based on the reflection coefficient parameters, and in response to determining that the antenna impedance is greater than or less than a threshold antenna impedance, iteratively tune the antenna using the multifunctional tuner.

Abstract: An electronic device may be provided with wireless circuitry and control circuitry. The wireless circuitry may include a phased antenna array. Sensors and other circuitry in the electronic device may generate sensor data such as accelerometer data, gyroscope data, magnetometer data, location data, and spatial ranging data. The wireless circuitry may establish and maintain one or more wireless links with external devices based on the sensor data as the device moves over time. For example, the wireless circuitry may perform physical layer beam adjustments, inter-radio access technology handovers, intra-radio access technology handovers, and/or dual connectivity adjustments based on the sensor data. This may allow the device to maintain one or more wireless links without having to sweep the signal beam of the phased antenna array over its entire field of view each time the device has moved.

Abstract: An electronic device may be provided with a cover layer and a phased antenna array mounted against the cover layer. Each antenna in the array may include a first patch element that is directly fed using first and second feeds and a second patch element that is directly fed using third and fourth feeds. A slot element may be formed in the first patch element. The first patch element may radiate in a first frequency band through the cover layer. The slot element may radiate in a second frequency band that is higher than the first frequency band through the cover layer. The second patch element may indirectly feed the slot element. Locating the radiating elements for each frequency band in the same plane may allow the antenna to radiate through the cover layer in both frequency bands with satisfactory antenna efficiency.

Abstract: An electronic device may be provided with a dielectric cover layer, a dielectric substrate, and a phased antenna array on the dielectric substrate for conveying millimeter wave signals through the dielectric cover layer. The array may include conductive traces mounted against the dielectric layer. The conductive traces may form patch elements or parasitic elements for the phased antenna array. The dielectric layer may have a dielectric constant and a thickness selected to form a quarter wave impedance transformer for the array at a wavelength of operation of the array. The substrate may include fences of conductive vias that laterally surround each of the antennas within the array. When configured in this way, signal attenuation, destructive interference, and surface wave generation associated with the presence of the dielectric layer over the phased antenna array may be minimized.

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. 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 a cover layer and a phased antenna array mounted against the cover layer. Each antenna in the array may include a first patch element that is directly fed using first and second feeds and a second patch element that is directly fed using third and fourth feeds. A slot element may be formed in the first patch element. The first patch element may radiate in a first frequency band through the cover layer. The slot element may radiate in a second frequency band that is higher than the first frequency band through the cover layer. The second patch element may indirectly feed the slot element. Locating the radiating elements for each frequency band in the same plane may allow the antenna to radiate through the cover layer in both frequency bands with satisfactory antenna efficiency.

Abstract: An electronic device may be provided with wireless circuitry and control circuitry. The wireless circuitry may include a phased antenna array. Sensors and other circuitry in the electronic device may generate sensor data such as accelerometer data, gyroscope data, magnetometer data, location data, and spatial ranging data. The wireless circuitry may establish and maintain one or more wireless links with external devices based on the sensor data as the device moves over time. For example, the wireless circuitry may perform physical layer beam adjustments, inter-radio access technology handovers, intra-radio access technology handovers, and/or dual connectivity adjustments based on the sensor data. This may allow the device to maintain one or more wireless links without having to sweep the signal beam of the phased antenna array over its entire field of view each time the device has moved.

Abstract: An electronic device may be provided with a dielectric cover layer and a conductive layer on the dielectric cover layer. The conductive layer may define an opening. A dielectric spacer may be mounted to the cover layer within the opening. A substrate may be mounted to the spacer. Vertical conductive structures may extend from the conductive layer to the substrate and may laterally surround the spacer. A phased antenna array may be formed on the substrate and aligned with the opening. The cover layer may have a dielectric constant and thickness that are selected to form a quarter wave impedance transformer for the array at a wavelength of operation of the array. The spacer and the conductive structures may exhibit a cavity resonance at the wavelength. The array and the conductive structures may radiate radio-frequency signals at millimeter wave frequencies through the dielectric cover layer.

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. Non-millimeter-wave antennas such as cellular telephone antennas may have conductive structures separated by a dielectric gap. In a device with a metal housing, a plastic-filled slot may form the dielectric gap. The conductive structures may be slot antenna structures, inverted-F antenna structures such as an inverted-F antenna resonating element and a ground, or other antenna structures. The plastic-filled slot may serve as a millimeter wave antenna window. A millimeter wave antenna array may be mounted in alignment with the millimeter wave antenna window to transmit and receive signals through the window. Millimeter wave antenna windows may also be formed from air-filled openings in a metal housing such as audio port openings.

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 such as a wristwatch may be provided with a phased antenna array for conveying first signals at a first frequency between 10 GHz and 300 GHz and a non-millimeter wave antenna for conveying second signals at a second frequency below 10 GHz. The device may include conductive housing sidewalls and a display. Conductive structures in the display and the conductive housing sidewalls may define a slot element in the non-millimeter wave antenna. The phased antenna array may be mounted within the slot element, aligned with a spatial filter in the display, or aligned with a dielectric window in the conductive housing sidewalls. Control circuitry may process signals transmitted by the phased antenna array and a reflected version of the transmitted signals that has been received by the phased antenna array to detect a range between the device and an external object.

Abstract: An electronic device such as a wristwatch may be provided with a phased antenna array for conveying first signals at a first frequency between 10 GHz and 300 GHz and a non-millimeter wave antenna for conveying second signals at a second frequency below 10 GHz. The device may include conductive housing sidewalls and a display. Conductive structures in the display and the conductive housing sidewalls may define a slot element in the non-millimeter wave antenna. The phased antenna array may be mounted within the slot element, aligned with a spatial filter in the display, or aligned with a dielectric window in the conductive housing sidewalls. Control circuitry may process signals transmitted by the phased antenna array and a reflected version of the transmitted signals that has been received by the phased antenna array to detect a range between the device and an external object.

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 be provided with wireless circuitry. The wireless circuitry may include one or more antennas. The antennas may include millimeter wave antenna arrays. Non-millimeter-wave antennas such as cellular telephone antennas may have conductive structures separated by a dielectric gap. In a device with a metal housing, a plastic-filled slot may form the dielectric gap. The conductive structures may be slot antenna structures, inverted-F antenna structures such as an inverted-F antenna resonating element and a ground, or other antenna structures. The plastic-filled slot may serve as a millimeter wave antenna window. A millimeter wave antenna array may be mounted in alignment with the millimeter wave antenna window to transmit and receive signals through the window. Millimeter wave antenna windows may also be formed from air-filled openings in a metal housing such as audio port openings.

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 multiple antennas each having multiple antenna feeds for covering different polarizations. Control circuitry may control the wireless circuitry to transmit signals at millimeter or centimeter wave frequencies using a first set of feeds in the array and at least one selected phase. The wireless circuitry may receive the signals transmitted by the first set of feeds using a second set of feeds in the array. The control circuitry may gather phase measurements for the received signals and may compare the phase measurements to the selected phase to generate phase difference values. The control circuitry may perform external object proximity detection operations based on the phase difference values. The control circuitry may control the wireless circuitry to cycle through different combinations of antenna feeds for the first and second sets.

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 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 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.