Abstract: An electronic device may be provided with a phased antenna array. Each antenna in the array may include a patch element having first, second, third, and fourth positive antenna feed terminals. The first and second terminals may convey first signals with a first polarization. The third and fourth terminals may convey second signals with a second polarization. Phase shifting components such as phase shifting transmission line segments or phase shifter circuits may ensure that the first signals at the first terminal are out of phase with respect to the first signals at the second terminal and may ensure that the second signals at the third terminal are out of phase with respect to the second signals at the fourth terminal. This may allow antenna current density for both polarizations to be symmetrically distributed about a normal axis of the patch element.

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 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 phased antenna array and a display cover layer. The phased antenna array may include a dielectric resonator antenna. The dielectric resonator antenna may include a dielectric resonating element embedded in a lower permittivity dielectric substrate. The substrate and the resonating element may be mounted to a flexible printed circuit. A slot may be formed in ground traces on the flexible printed circuit and aligned with the resonating element. The slot may excite resonant modes of the resonating element. The resonating element may convey corresponding radio-frequency signals through the cover layer. A dielectric matching layer may be interposed between the resonating element and the cover layer. If desired, the slot may radiate additional radio-frequency signals and the matching layer may have a tapered shape. Dielectric resonator antennas for covering different polarizations and frequencies may be interleaved across the array.

Abstract: An electronic device may be provided with wireless circuitry and control circuitry. The wireless circuitry may communicate using a 5G New Radio (NR) protocol. The wireless circuitry may have multiple bandwidth part configurations. The control circuitry may place the wireless circuitry in a first bandwidth part configuration where a first bandwidth part of a first component carrier is active and a second bandwidth part of a second component carrier is inactive. The control circuitry may switch the wireless circuitry from the first bandwidth part configuration to a second bandwidth part configuration in which the first bandwidth part is inactive and the second bandwidth part is active. The first and second component carriers may be intra-band contiguous, intra-band non-contiguous, or inter-band. The control circuitry may switch the wireless circuitry into other configurations for covering other bandwidth parts of any desired component carriers in any desired bands.

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 an antenna, a display, and a housing. The display may include a conductive display structure and a cover layer. The housing may include peripheral conductive structures and a conductive rear wall. The peripheral structures may include a ledge separated from the conductive display structure by a gap. The peripheral structures and the rear wall may define opposing edges of a slot element for the antenna. Conductive bridging structures may be coupled between the conductive display structure and the ledge across the gap. The bridging structures may at least partially overlap locations along the length of the slot element where antenna currents around the slot element exhibit a maximum magnitude. The bridging structures may align the phase of current induced on the ledge with the phase of the current induced on the conductive display structure to maximize antenna efficiency through the cover layer.

Abstract: An electronic device housing may have a rear housing wall that forms a metal ground plane. A slot may be formed in the metal ground plane. The slot may have one or more open ends along an edge of the ground plane. A near-field communications loop antenna may overlap the slot. The near-field communications loop antenna may have one or more turns. A current path through the metal ground plane may form one of the turns in the near-field communications loop antenna. The slot may form portions of non-near-field-communications antennas in addition to the near-field communications loop antenna. The slot in the non-near-field-communications antennas may be fed using an indirect antenna feed structure. Components such as a capacitor and inductor may help allow non-near-field communications antenna and the near-field communications antenna to be formed from common portions of the metal ground plane.

Abstract: An electronic device may include first, second, and third antennas and conductive housing structures. The first, second, and third antennas may each include slots having open ends defined by gaps in the conductive housing structures. The second antenna may be interposed between the first and third antennas. The first and second antennas may convey signals at the same frequencies. The third antenna may convey signals at a lower frequency than the first and second antennas. A switch may be coupled across the third slot and may have a first state at which the switch forms a closed end of the third slot and a second state at which the third slot has two opposing open ends. Control circuitry may selectively activate one of two feeds for the third antenna and may adjust the switch so that the third antenna exhibits satisfactory antenna efficiency regardless of environmental conditions for the device.

Abstract: An electronic device may be provided with a phased antenna array and a display cover layer. The phased antenna array may include a dielectric resonator antenna. The dielectric resonator antenna may include a dielectric resonating element embedded in a lower permittivity dielectric substrate. The substrate and the resonating element may be mounted to a flexible printed circuit. A slot may be formed in ground traces on the flexible printed circuit and aligned with the resonating element. The slot may excite resonant modes of the resonating element. The resonating element may convey corresponding radio-frequency signals through the cover layer. A dielectric matching layer may be interposed between the resonating element and the cover layer. If desired, the slot may radiate additional radio-frequency signals and the matching layer may have a tapered shape. Dielectric resonator antennas for covering different polarizations and frequencies may be interleaved across the array.

Abstract: An electronic device may include a peripheral conductive housing sidewall with an integral ledge extending towards the device interior. A display cover layer may be supported by the integral ledge. A slot antenna may be formed from a slot in the integral ledge. The integral ledge may be mounted to a surface of a substrate and coupled to a conductive rear housing wall by a conductive layer extending over an additional surface of the substrate. The sidewall may include a vertical portion extending from the ledge to the rear wall. The slot antenna may be fed via near-field coupling using a conductive patch that is located within the slot at the surface of the substrate. The conductive layer, rear housing wall, and vertical portion may form a cavity for the slot antenna. The conductive layer may isolate the slot from interference with a battery, display circuitry, or other components.

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 control circuitry and doublets of first and second antennas that are used to determine the position and orientation of the device relative to external wireless equipment. The control circuitry may determine the relative position and orientation of the external equipment by measuring the angle of arrival of radio-frequency signals from the external equipment. Each doublet may include first and second cavity-backed slot antennas. The first and second antennas may each include a first slot element that is directly fed and a second slot element that is parasitically fed by the first slot element. The first slot element may radiate in an ultra-wideband communications band at 8.0 GHz and the second slot element may radiate in an ultra-wideband communications band at 6.5 GHz. The doublet may be aligned with a dielectric window in a conductive sidewall for the device.

Abstract: An electronic device may be provided with a phased antenna array and a display cover layer. The phased antenna array may include a dielectric resonator antenna. The dielectric resonator antenna may include a dielectric resonating element embedded in a lower permittivity dielectric substrate. The substrate and the resonating element may be mounted to a flexible printed circuit. A slot may be formed in ground traces on the flexible printed circuit and aligned with the resonating element. The slot may excite resonant modes of the resonating element. The resonating element may convey corresponding radio-frequency signals through the cover layer. A dielectric matching layer may be interposed between the resonating element and the cover layer. If desired, the slot may radiate additional radio-frequency signals and the matching layer may have a tapered shape. Dielectric resonator antennas for covering different polarizations and frequencies may be interleaved across the array.

Abstract: An electronic device may be provided with control circuitry and doublets of first and second antennas that are used to determine the position and orientation of the device relative to external wireless equipment. The control circuitry may determine the relative position and orientation of the external equipment by measuring the angle of arrival of radio-frequency signals from the external equipment. Each doublet may include first and second cavity-backed slot antennas. The first and second antennas may each include a first slot element that is directly fed and a second slot element that is parasitically fed by the first slot element. The first slot element may radiate in an ultra-wideband communications band at 8.0 GHz and the second slot element may radiate in an ultra-wideband communications band at 6.5 GHz. The doublet may be aligned with a dielectric window in a conductive sidewall for the device.

Abstract: An electronic device may have peripheral conductive structures and a conductive layer that define edges of a slot element for a slot antenna. The slot element may be configured to cover wireless communications in a 1575 MHz satellite navigation band and 2.4 GHz and 5 GHz wireless local area network bands. A tuning circuit may be coupled across the slot approximately half way across the length of the slot. The antenna tuning circuit may include an inductor coupled in series with a notch filter (in scenarios where the slot is long enough to cover the 1575 MHz satellite navigation band in its fundamental mode) or may include a capacitor coupled in series with a notch or low pass filter. The fundamental mode and one or more harmonic modes of the slot element may cover the satellite navigation and wireless local area network bands.

Abstract: An electronic device may be provided antennas and control circuitry. The antennas may be arranged in an array of unit cells. Each unit cell may include a first antenna that conveys signals in a first frequency band higher than 10 GHz and a second antenna that conveys radio-frequency signals in a second frequency band higher than the first frequency band. A first of the unit cells may be provided with a first set of antennas that transmits radio-frequency signals in a third frequency band higher than the second frequency band. A second of the antenna unit cells may be provided with a second set of antennas that receives the radio-frequency signals after being reflected off of external objects. The control circuitry may perform spatial ranging operations by processing the transmitted and received signals in the second frequency band.

Abstract: An electronic device may be provided with antenna structures that convey radio-frequency signals greater than 10 GHz. The antenna structures may include overlapping first and second patches. The first patch may include a hole. A transmission line for the second patch may include a conductive via extending through the hole. The via may be coupled to a first end of a trace. A second end of the trace may be coupled to a feed terminal on the second patch over an additional via. The hole may be located within a central region of the first patch to allow the via to pass through the hole without electromagnetically coupling to the first patch. If desired, adjustable impedance matching circuits may be used to couple selected impedances to the antenna feeds that help ensure that the first and second patch antennas are sufficiently isolated from each other.

Abstract: An electronic device may be provided with wireless circuitry that includes a radio-frequency transceiver circuit and an antenna. The antenna may be a patch antenna formed from a patch antenna resonating element and an antenna ground. The patch antenna resonating element may be formed from a metal patch on a printed circuit board. The antenna ground may be formed from a metal housing having a planar rear wall that lies in a plane parallel to the metal patch. The radio-frequency transceiver circuit may be coupled to the metal patch through traces on the printed circuit and may be coupled to rear wall of the housing through a screw and a screw boss in the housing. Buttons and other electrical components may be mounted on the printed circuit board and may be coupled to control circuitry on the printed circuit board through the metal patch.