Abstract: An electronic device may include a transmission line path having a signal conductor embedded in a substrate. A contact pad may be patterned on a surface of the substrate. A radio-frequency component may be mounted to the contact pad using solder. Multi-layer impedance matching structures may couple the signal conductor to the contact pad. The matching structures may include a set of via pads and a set of conductive vias coupled in series between the signal conductor and the contact pad. The area of the via pads may vary across the set of via pads and/or the aspect ratio of the conductive vias may vary across the set of conductive vias. The matching structures may perform impedance matching between the signal conductor and the radio-frequency component at frequencies greater than 10 GHz while occupying a minimal amount of space in the device.

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 a transceiver, a substrate, and antennas mounted to the substrate. The transceiver and antennas may convey signals between 10 GHz and 300 GHz. A radio-frequency connector may be mounted to the substrate. A coaxial cable may couple the transceiver to the connector. A stripline in the substrate may couple the connector to the antennas. Impedance matching structures may be embedded in the substrate for matching an impedance of the stripline to an impedance of the coaxial cable. The impedance matching structures may include a fence of conductive vias, landing pads, and a volume of the dielectric substrate defined by the fence of conductive vias and the landing pads. The impedance matching structures may be configured to perform impedance matching over a relatively wide bandwidth that includes the frequency band of operation for the antennas.

Abstract: An electronic device may be provided with a phased antenna array that radiates at a frequency greater than 10 GHz through a display. The array may include a dielectric resonator antenna having a dielectric column. The dielectric column may have a first surface mounted to a circuit board and a second surface that faces the display. A conductive cap may be formed on the second surface. The conductive cap may allow the dimensions of dielectric column to be reduced while still allowing the dielectric resonator antenna to cover a frequency band of interest. If desired, the phased antenna array may include multiple sets of dielectric resonator antennas for covering different frequency bands. The sets may have different dielectric column heights and/or different conductive cap sizes.

Abstract: An electronic device may be provided with a conductive sidewall. An aperture may be formed in the sidewall. The sidewall may have a cavity that extends from the aperture towards the interior of the device. The cavity may be filled with an injection-molded plastic substrate. A dielectric block having a dielectric constant greater than that of the injection-molded plastic substrate and the antenna layers may be embedded in the injection-molded plastic substrate. The dielectric block may at least partially overlap an antenna. The antenna may convey radio-frequency signals at a frequency greater than 10 GHz through the cavity, the dielectric block, the injection-molded plastic substrate, and the aperture. The dielectric block may increase the effective dielectric constant of the cavity, allowing the antenna to cover relatively low frequencies without increasing the size of the aperture.

Abstract: An electronic device may be provided with a sidewall and an antenna module pressed against an interior surface of the sidewall. The module may include a phased antenna array. The sidewall may have apertures aligned with respective antenna in the array. The antennas may convey radio-frequency signals in first and second frequency bands greater than 10 GHz and with vertical and horizontal polarizations. Each aperture may include a corresponding cavity with non-linear cavity walls. The antennas may excite resonant cavity modes of the cavities that cause the cavities to radiate the radio-frequency signals as waveguide radiators. At the same time, the apertures may form a smooth impedance transition between the antennas and free space for the radio-frequency signals of both the horizontal and vertical polarizations.

Abstract: An electronic device may be provided with an antenna module having a substrate. A phased antenna array of dielectric resonator antennas and a radio-frequency integrated circuit for the array may be mounted to one or more surfaces of the substrate. The dielectric resonator antennas may include dielectric columns excited by feed probes. The feed probes may be printed onto sidewalls of the dielectric columns or may be pressed against the sidewalls by biasing structures. A plastic substrate may be molded over each dielectric column and each of the feed probes in the array. The feed probes may cover multiple polarizations. The array may include elements for covering multiple frequency bands. The dielectric columns may be aligned a longitudinal axis and may be rotated at a non-zero and non-perpendicular angle with respect to the longitudinal axis.

Abstract: An electronic device may be provided with a phased antenna array and a display cover layer. The phased antenna array may include a probe-fed dielectric resonator antenna that radiates through the cover layer. The antenna may include a dielectric resonating element that is excited by one or two feed probes. One or more floating parasitic elements and/or grounded parasitic elements may be patterned onto the dielectric resonating element. The parasitic elements may create boundary conditions on the dielectric resonating element that serve to isolate the antenna from cross polarization interference.

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 phased antenna array. The array may convey signals greater than 10 GHz and may be formed on a substrate having transmission line layers and antenna layers. An antenna in the array may have a radiating element that includes first, second, and third overlapping patch elements on the antenna layers. The antenna may be fed using a differential transmission line coupled to a differential feed on the first patch element. The differential transmission line may include first and second signal traces. A first via may couple the first signal trace to the first, second, and third patch elements. A second via may couple the second signal trace to the first, second, and third patch elements. The patch elements may introduce capacitances to the radiating element that help to compensate for inductances associated with the distance between the radiating element and the signal traces.

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 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: A mobile phone includes a housing structure, the housing structure defining a side surface of the mobile phone, a front cover coupled to the housing structure and defining a front surface of the mobile phone, a rear cover coupled to the housing structure and defining a rear surface of the mobile phone, a display positioned below the front cover, a first directional antenna defining a first radiation pattern extending through the front surface of the mobile phone, a second directional antenna defining a second radiation pattern extending through the rear surface of the mobile phone, and a third directional antenna defining a third radiation pattern extending through the side surface of the mobile phone.

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 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 a phased antenna array. The array may convey signals greater than 10 GHz and may be formed on a substrate having transmission line layers and antenna layers. An antenna in the array may have a radiating element that includes first, second, and third overlapping patch elements on the antenna layers. The antenna may be fed using a differential transmission line coupled to a differential feed on the first patch element. The differential transmission line may include first and second signal traces. A first via may couple the first signal trace to the first, second, and third patch elements. A second via may couple the second signal trace to the first, second, and third patch elements. The patch elements may introduce capacitances to the radiating element that help to compensate for inductances associated with the distance between the radiating element and the signal traces.

Abstract: An electronic device may be provided with a phased antenna array and a display cover layer. The phased antenna array may include a probe-fed dielectric resonator antenna. The antenna may include a dielectric resonating element mounted to a flexible printed circuit. A feed probe may be formed from a patch of conductive traces on a sidewall of the resonating element. The feed probe may excite resonant modes of the resonating element. The resonating element may convey corresponding radio-frequency signals through the display cover layer. An additional feed probe may be mounted to an orthogonal sidewall of the resonating element for covering additional polarizations. Probe-fed dielectric resonator antennas for covering different polarizations and frequencies may be interleaved across the phased antenna array.