Abstract: An electronic device can include a housing, a display positioned within the housing; and a cover glass disposed over the display and attached to the housing. The cover glass can include a glass sheet; a hard coat layer disposed on the glass sheet, having a hardness greater than a hardness of the glass sheet; and a gradient layer deposited on the hard coat layer and having a composition that transitions from a first composition at the hard coat layer to a second composition at a top surface of the gradient layer. The first composition can be predominantly a composition of the hard coat layer and the second composition is different than the first composition. The second composition can be predominantly SiO2. The hard coat layer can include SiON. The cover glass can include an intermediate gradient layer disposed between the glass sheet and the hard coat layer.

Abstract: Electronic devices may be provided with optical components such as displays and sensors that emit and/or detect visible and/or infrared light. The optical components may be mounted in a housing and covered by a textured glass cover layer. The textured glass cover layer may have an antireflection coating formed from a stack of alternating higher index and lower index inorganic dielectric layers. An outermost one of the inorganic dielectric layers may have a hardness greater than quartz to help the antireflection coating resist abrasion. The coating may optionally include a layer of diamond-like carbon to reduce friction and an oleophobic polymer coating to resist fingerprint smudging.

Abstract: An electronic device may be surrounded by an exterior region and may have an interior region. Electronic components may be mounted in the interior region. Housing walls such as housing walls formed from transparent layers of material may separate the interior region from the exterior region. A display may be visible through one of the transparent layers of material. A transparent layer of material may be coupled to housing structures in the device and may be formed of glass or glass-ceramic. The transparent layer may have two opposing chemically strengthened surface layers of different thicknesses. A coating may be formed on a thinner of the two opposing chemically strengthened surface layers. The coating may have an oleophobic outer coating layer, an antireflection layer, and an antiscratch layer. The antiscratch layer may have one or more compressively stressed dielectric layers and may have one or more corresponding graded composition layers.

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 antireflective infrared cut filter coating may be applied on transparent substrates within electronic devices, such as sapphire or glass substrates. The transparent substrates may be windows for optical components or may be cover glasses for displays. The antireflective infrared cut filter coating may be formed from a thin-film interference filter having a plurality of thin-film layers of varying materials and thicknesses. The antireflective infrared cut filter coating may transmit light neutrally across visible wavelengths and may reflect infrared light. In this way, the antireflective infrared cut filter coating may reduce unwanted infrared light from reaching underlying optical components, such as wide-angle cameras, thereby reducing undesirable artifacts in images generated by the components.

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.