Abstract: An electronic device may include first and second antennas formed from respective first and second segments of a housing. The first antenna may have a first feed coupled to the first segment by a first switch and coupled to the first segment by a first conductive trace. The second antenna may have a second feed coupled to the second segment by a second switch and coupled to the second segment by a second conductive trace. The first segment may be separated from the second segment by a single gap, a data connector may pass through the second segment, and the antennas may selectively cover a low band. Alternatively, the first segment may be separated from the second segment by a third segment and two gaps, the data connector may pass through the third segment, and the first and second antennas may concurrently cover the low band.

Abstract: An electronic device may include an antenna disposed on a substrate. The antenna may include a ring of conductive traces, a fed arm, and an unfed arm. The fed arm and the unfed arm may extend from opposing segments of the ring. The ring may be coupled to ground by fences of conductive vias extending through the substrate. The first arm may have a first radiating edge. The second arm may have a second radiating edge. The first radiating edge may be separated from the second radiating edge by a gap. The first arm may indirectly feed the second arm via near-field electromagnetic coupling across the gap. The first and second arms may collectively radiate in an ultra-wideband (UWB) frequency band.

Abstract: An electronic device may include first and second antennas formed from respective first and second segments of a housing. The first antenna may have a first feed coupled to the first segment by a first switch and coupled to the first segment by a first conductive trace. The second antenna may have a second feed coupled to the second segment by a second switch and coupled to the second segment by a second conductive trace. The first segment may be separated from the second segment by a single gap, a data connector may pass through the second segment, and the antennas may selectively cover a low band. Alternatively, the first segment may be separated from the second segment by a third segment and two gaps, the data connector may pass through the third segment, and the first and second antennas may concurrently cover the low band.

Abstract: An electronic device may include first and second antennas formed from respective first and second segments of a housing. The first antenna may have a first feed coupled to the first segment by a first switch and coupled to the first segment by a first conductive trace. The second antenna may have a second feed coupled to the second segment by a second switch and coupled to the second segment by a second conductive trace. The first segment may be separated from the second segment by a single gap, a data connector may pass through the second segment, and the antennas may selectively cover a low band. Alternatively, the first segment may be separated from the second segment by a third segment and two gaps, the data connector may pass through the third segment, and the first and second antennas may concurrently cover the low band.

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 an antenna module. A phased antenna array of dielectric resonator antennas may be disposed within the antenna module. The dielectric resonator antennas may include dielectric columns excited by feed probes. A flexible printed circuit may include transmission lines coupled to the feed probes. The flexible printed circuit may have a first end coupled to the antenna module and extending towards peripheral conductive housing structures forming an additional antenna and a second end coupled to transceiver circuitry. Ground traces on the flexible printed circuit may be shorted to ground structures at the first and second ends to improve the antenna efficiency of the additional antenna. The flexible printed circuit may include an elongated slot with overlapping conductive structures and laterally surrounded by a fence of conductive vias to improve the flexibility of the flexible printed circuit while providing satisfactory antenna performance.

Abstract: An electronic device may have peripheral conductive housing structures, a display frame, a support plate, a logic board, and an antenna. The antenna may have a resonating element that includes a first slot between the logic board and a segment of the peripheral conductive housing structures, a second slot between the display frame and the segment, and optionally a third slot between the between the support plate and the segment. The slots may be at least partially overlapping, may have respective lengths, may be located at respective distances from a cover layer for the display, and may collectively receive radio-frequency signals in a frequency band such as the L5 GPS band. Switching circuitry and filter circuitry may be coupled to the antenna feed and/or to the antenna feed(s) of one or more adjacent antennas in the electronic device to help to isolate the antennas from each other.

Abstract: An electronic device may be provided with wireless circuitry and a housing with upper and lower ends. The upper end may include first and second inverted-F antennas formed from portions of conductive peripheral housing structures separated from an antenna ground by a slot. The upper end may include an open slot antenna formed from a portion of the slot. The upper end may include an additional inverted-F antenna that overlap the slot. A parasitic element may be disposed between the open slot antenna and the additional inverted-F antenna and coupled to the antenna ground at a proximal end. A tuning component may be coupled between the parasitic element and the antenna ground.

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 a housing with upper and lower ends. The lower end may include first and second open slot antennas that are directly fed by respective feeds and that radiate in a cellular ultra-high band. The lower end may also include first and second inverted-F antennas. The upper end may include third and fourth inverted-F antennas. The first inverted-F antenna may have a first feed that conveys currents below 2700 MHz and a second feed that conveys antenna currents in the cellular ultra-high band, a wireless local area network band, and/or ultra-wideband frequency bands. If desired, the upper end may include a third open slot antenna that is directly fed by a corresponding antenna feed and that radiates in the cellular ultra-high band and/or in the ultra-wideband frequency bands.

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 and a housing with upper and lower ends. The upper end may include first and second inverted-F antennas formed from portions of conductive peripheral housing structures separated from an antenna ground by a slot. The upper end may include an open slot antenna formed from a portion of the slot. The upper end may include an additional inverted-F antenna that overlap the slot. A parasitic element may be disposed between the open slot antenna and the additional inverted-F antenna and coupled to the antenna ground at a proximal end. A tuning component may be coupled between the parasitic element and the antenna ground.

Abstract: An electronic device may be provided with an antenna module. A phased antenna array of dielectric resonator antennas may be disposed within the antenna module. The dielectric resonator antennas may include dielectric columns excited by feed probes. A flexible printed circuit may include transmission lines coupled to the feed probes. The flexible printed circuit may have a first end coupled to the antenna module and extending towards peripheral conductive housing structures forming an additional antenna and a second end coupled to transceiver circuitry. Ground traces on the flexible printed circuit may be shorted to ground structures at the first and second ends to improve the antenna efficiency of the additional antenna. The flexible printed circuit may include an elongated slot with overlapping conductive structures and laterally surrounded by a fence of conductive vias to improve the flexibility of the flexible printed circuit while providing satisfactory antenna performance.

Abstract: An electronic device may be provided with wireless circuitry and a housing with upper and lower ends. The lower end may include first and second open slot antennas that are directly fed by respective feeds and that radiate in a cellular ultra-high band. The lower end may also include first and second inverted-F antennas. The upper end may include third and fourth inverted-F antennas. The first inverted-F antenna may have a first feed that conveys currents below 2700 MHz and a second feed that conveys antenna currents in the cellular ultra-high band, a wireless local area network band, and/or ultra-wideband frequency bands. If desired, the upper end may include a third open slot antenna that is directly fed by a corresponding antenna feed and that radiates in the cellular ultra-high band and/or in the ultra-wideband frequency bands.

Abstract: An electronic device may be provided with first, second, and third antennas and a dock flex. A first feed terminal for the first antenna may be coupled to a second feed terminal for the second antenna over a first path. The first path may be coupled to ground over a second path. Tuning components may be interposed on the first and second paths. The third antenna may be patterned on a first portion of the dock flex. Front end components for the first antenna may be mounted to a second portion of the dock flex. The first and second portions may extend from a tail of the dock flex. The tail may be wrapped around a plastic support block to hold the second portion over the first portion. The plastic support block may have a snap hook clip that holds the second portion in place.

Abstract: A device with near-field communications (NFC) capabilities is provided. A housing may include first and second segments and a support plate separated from the segments by a slot. A first inductor may be coupled between the first segment and the plate. A second inductor may be coupled between the second segment and the plate. A transceiver may have a first signal terminal coupled to the first segment over a first path and a second signal terminal coupled to the second segment over a second path. The transceiver may convey differential signals in an NFC band over a loop path for an NFC antenna that includes the first conductive path, the first segment, the first inductor, a portion of the plate between the first and second inductors, the second inductor, the second segment, and the second conductive path. This may optimize wireless performance and volume for the NFC antenna.

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 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 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 ground structures and peripheral conductive housing structures defining opposing edges of a slot element. A monopole element may overlap the slot element. The monopole element may be directly fed radio-frequency signals by an antenna feed coupled to the monopole element. The monopole element may radiate the radio-frequency signals in a first frequency band while indirectly feeding the radio-frequency signals to the slot element via near-field electromagnetic coupling. The slot element may radiate the radio-frequency signals in a second frequency band that is lower than the first frequency band. The monopole element and the slot element may collectively form a multi-band antenna that exhibits a relatively wide bandwidth.