Abstract: An electronic device may be provided with an antenna for receiving signals in first and second ultra-wideband communications bands. The antenna may include a shielding ring that runs around first and second arms. The first arm may radiate in the first band and the second arm may radiate in the second band. The first arm may have an end formed from a first segment of the ring and a radiating edge facing the second arm. The second arm may have an end formed from a second segment of the ring and a radiating edge facing the first arm. First and second sets of conductive vias may couple the ring to ground. The first set may form a return path for the first arm. The second set may form a return path for the second arm.

Abstract: An electronic device may be provided with a housing, a logic board, and wireless circuitry on the logic board. The wireless circuitry may include first and second antennas formed from conductive traces on a surface of the logic board. The first and second antennas may include resonating element arms at opposing sides of the logic board. The first antenna may have a fundamental mode that radiates in a Bluetooth® communications band at 2.4 GHz. The second antenna may radiate in a first ultra-wideband communications band such as a 6.5 GHz ultra-wideband communications band. If desired, the second antenna may also radiate in a second ultra-wideband communications band such as an 8.0 GHz ultra-wideband communications band. In another suitable arrangement, a harmonic mode of the first antenna may radiate in the second ultra-wideband communications band.

Abstract: An electronic device may be provided with wireless circuitry that includes first, second, and third antennas used to determine the position and orientation of the electronic device relative to external equipment. The antennas may include patch elements on respective substrates mounted to a flexible printed circuit. Each substrate may include fences of conductive vias that are coupled to ground and that laterally surround the corresponding patch element. Control circuitry may identify phase differences between the first and second antennas and between the second and third antennas and may identify an angle of arrival of received ultra-wideband signals using the phase differences. The control circuitry may compare the phase differences to a set of predetermined surfaces of phase differences to identify environmental loading conditions for the antenna. The control circuitry may correct the angle of arrival using offsets identified based on the environmental loading conditions.

Abstract: An electronic device may be provided with wireless circuitry that is tested in a test system. The test system may include test probes. Circuitry under test may wirelessly transmit test signals. The test probes may receive the test signals at multiple locations. Circuitry may measure direct current (DC) voltages generated by the test probes and may convert the voltages to electric field magnitudes. A test host may process the electric field magnitudes to determine whether the circuitry under test exhibits a satisfactory radiation pattern. The test probes may include dielectric substrates and one or more dipole elements coupled to respective diodes. The dipole elements may include indium tin oxide (ITO) and may include first and second sets of orthogonal dipole elements. Transmission lines coupled to the dipole elements may include ITO and may form low pass filters that convert rectified voltages produced by the diodes into the DC voltages.

Abstract: An electronic device may be provided with antennas for receiving signals in first and second ultra-wideband communications bands. The antennas may include a resonating element formed from conductive traces on a dielectric substrate. The substrate may be mounted to an underlying flexible printed circuit. A fence of conductive vias may extend from the resonating element, through the substrate and the flexible printed circuit, to a ground plane on the flexible printed circuit. The fence may form a return path for the antenna. A shielding ring may be formed on the substrate. Additional fences of vias may couple the shielding ring to the ground plane. If desired, the resonating element may include a patch that is not shorted to the ground plane. The fences of vias, the conductive traces, and the ground plane may form a continuous antenna cavity for the resonating element.

Abstract: Aspects of the subject technology relate to electronic devices with antennas. The antenna may be a display-integrated antenna. An antenna feed for the antenna may be located in a recess in a sidewall of a housing of the device. The antenna feed may be coupled to transceiver circuitry on a logic board of the device by a pair of flex circuits. A first one of the pair of flex circuits may form a portion of an antenna feed assembly. A second one of the pair of flex circuits may be an impedance-matching flex having an end that is soldered to the main logic board. The antenna may be coupled to a conductive portion of the housing of the device.

Abstract: An electronic device may be provided with an antenna for receiving signals in first and second ultra-wideband communications bands. The antenna may include a first arm that radiates in the first band and a second arm that radiates in the second band. The antenna may be fed by a stripline. A microstrip may couple the stripline to the first and second arms and may be configured to match the impedance of the stripline to the impedance of the first and second arms in the first and second bands, respectively. Sets of antennas tuned to different frequencies may be fed by the same transmission line and may collectively exhibit a relatively wide bandwidth. A conductive shielding layer or other conductive components may be layered over the antennas to mitigate cross-polarization interference at the antennas.

Abstract: An electronic device such as a wireless earbud may have antenna structures that are configured to form one or more antenna portions or antennas for transmitting and receiving wireless signals. The device may include control circuitry that is configured to selectively activate one or more antennas or antenna portions to transmit and receive wireless signals for the device. The device may include sensor circuitry that provide sensor data to the control circuitry. The control circuitry may use the sensor data to select and activate an optimal antenna based on the orientation of the earbud or the environment of the device. The antennas may be formed on opposing sides of a housing for the device. By providing configurable antenna structures, the device may be configured to adapt to the current environment and efficiently perform communications operations.

Abstract: An electronic device may be provided with antennas for receiving signals in first and second ultra-wideband communications bands. The antennas may include a resonating element formed from conductive traces on a dielectric substrate. The substrate may be mounted to an underlying flexible printed circuit. A fence of conductive vias may extend from the resonating element, through the substrate and the flexible printed circuit, to a ground plane on the flexible printed circuit. The fence may form a return path for the antenna. A shielding ring may be formed on the substrate. Additional fences of vias may couple the shielding ring to the ground plane. If desired, the resonating element may include a patch that is not shorted to the ground plane. The fences of vias, the conductive traces, and the ground plane may form a continuous antenna cavity for the resonating element.

Abstract: An electronic device may be provided with a housing, a logic board, and wireless circuitry on the logic board. The wireless circuitry may include first and second antennas formed from conductive traces on a surface of the logic board. The first and second antennas may include resonating element arms at opposing sides of the logic board. The first antenna may have a fundamental mode that radiates in a Bluetooth® communications band at 2.4 GHz. The second antenna may radiate in a first ultra-wideband communications band such as a 6.5 GHz ultra-wideband communications band. If desired, the second antenna may also radiate in a second ultra-wideband communications band such as an 8.0 GHz ultra-wideband communications band. In another suitable arrangement, a harmonic mode of the first antenna may radiate in the second ultra-wideband communications band.

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 be provided with wireless circuitry that includes antenna structures used to determine the position and orientation of the electronic device relative to external wireless equipment. The electronic device may include a housing having a planar conductive layer, a first slot antenna that includes a first bent slot element in the planar conductive layer, and a second slot antenna that includes a second bent slot element in the planar conductive layer. The first and second bent slot elements may be configured to receive radio-frequency signals at the same frequency. The first and second bent slot elements may have the same shape. The electronic device may include control circuitry configured to measure a phase difference between the radio-frequency signals received by the first and second slot antennas. The control circuitry may identify an angle of arrival of the received radio-frequency signals based on the measured phase difference.

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 be provided with an antenna for receiving signals in first and second ultra-wideband communications bands. The antenna may include a first arm that radiates in the first band and a second arm that radiates in the second band. The antenna may be fed by a stripline. A microstrip may couple the stripline to the first and second arms and may be configured to match the impedance of the stripline to the impedance of the first and second arms in the first and second bands, respectively. Sets of antennas tuned to different frequencies may be fed by the same transmission line and may collectively exhibit a relatively wide bandwidth. A conductive shielding layer or other conductive components may be layered over the antennas to mitigate cross-polarization interference at the antennas.

Abstract: An electronic device such as a wristwatch may have a housing with metal sidewalls and a display having conductive display structures. Printed circuits having corresponding ground traces may be coupled to the display for conveying data to and/or from the display. The conductive display structures may be separated from the metal sidewalls by a gap. A conductive interconnect may be coupled to the metal sidewalls and may extend across the gap to the conductive display structures. The conductive interconnect may be coupled to the ground traces on the printed circuits and/or may be shorted or capacitively coupled to the conductive display structures. When configured in this way, the metal sidewalls, the conductive display structures, and the conductive interconnect may define the edges of a slot antenna resonating element for a slot antenna.

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 wireless circuitry that is tested in a test system. The test system may include test probes. Circuitry under test may wirelessly transmit test signals. The test probes may receive the test signals at multiple locations. Circuitry may measure direct current (DC) voltages generated by the test probes and may convert the voltages to electric field magnitudes. A test host may process the electric field magnitudes to determine whether the circuitry under test exhibits a satisfactory radiation pattern. The test probes may include dielectric substrates and one or more dipole elements coupled to respective diodes. The dipole elements may include indium tin oxide (ITO) and may include first and second sets of orthogonal dipole elements. Transmission lines coupled to the dipole elements may include ITO and may form low pass filters that convert rectified voltages produced by the diodes into the DC voltages.

Abstract: An electronic device may be provided with antennas for receiving signals in first and second ultra-wideband communications bands. The antennas may include a resonating element formed from conductive traces on a dielectric substrate. The substrate may be mounted to an underlying flexible printed circuit. A fence of conductive vias may extend from the resonating element, through the substrate and the flexible printed circuit, to a ground plane on the flexible printed circuit. The fence may form a return path for the antenna. A shielding ring may be formed on the substrate. Additional fences of vias may couple the shielding ring to the ground plane. If desired, the resonating element may include a patch that is not shorted to the ground plane. The fences of vias, the conductive traces, and the ground plane may form a continuous antenna cavity for the resonating element.

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.