Abstract: An antenna element includes an insulative substrate including first and second main surfaces arranged in an up-down direction. At least one antenna conductor layer is provided on the first main surface of the insulative substrate. At least one insulative substrate non-forming region is provided between the insulative substrate and the antenna conductor layer in the up-down direction. An insulator layer does not exist in the at least one insulative substrate non-forming region. When seen in the up-down direction, all of an outer boundary of at least one antenna conductor overlaps the at least one insulative substrate non-forming region and is not in contact with the insulative substrate. At least one of the at least one insulative substrate non-forming region includes a void.

Abstract: An antenna element includes a first opening including an annular outer boundary in an antenna conductor layer. A first insulative substrate non-forming region is provided between an insulative substrate and the antenna conductor layer in an up-down direction. The insulative substrate does not exist in the first insulative substrate non-forming region. The outer boundary of the first opening overlaps one or more first insulative substrate non-forming regions and is not in contact with the insulative substrate. The first insulative substrate non-forming region is a first void, and a low dielectric constant material having a lower dielectric constant than that of a material of the insulative substrate or a high dielectric constant material having a higher dielectric constant than that of the material of the insulative substrate is provided in the first insulative substrate non-forming region.

Abstract: An antenna installation structure includes an antenna substrate, an insulation layer, and a bonding material. The antenna substrate includes a dielectric base including first and second main surfaces, and an antenna conductor on the first main surface. The insulation layer is on the first main surface of the antenna substrate. The bonding material is between the insulation layer and a radiation side wall of a housing, is cured, and bonds the insulation layer to the radiation side wall. A linear expansion coefficient of the insulation layer is lower than a linear expansion coefficient of the bonding material and higher than a linear expansion coefficient of the antenna substrate.

Abstract: In a transmission line, a thickness of a second section is smaller than that of a first section and of a third section. A center of the second section is above a center of the first section and a center of the third section in a laminated body up-down direction. A distance between a second signal conductor layer and a neutral plane of the second section is shorter than a distance between a first signal conductor layer and a neutral plane of the second section and a distance between a third signal conductor layer and a neutral plane of the second section in the laminated body up-down direction. A length of the second signal conductor layer between first and second interlayer connection conductors is equal to or less than about ½ of a wavelength of a high-frequency signal transmitted by the transmission line.

Abstract: A circuit board includes a first circuit board portion and a second circuit board portion. The first circuit board portion is provided with a first transmission line for a low-frequency signal or a low-speed signal, and the second circuit board portion is provided with a second transmission line for a high-frequency signal or a high-speed signal. The second circuit board portion is located on the first circuit board portion in a positional relationship in which the first transmission line and the second transmission line are side-by-side with each other. With this structure, signal leakage and interference between different signals are reduced or prevented in a line that transmits signals with different frequencies and different transmission speeds.

Abstract: An electronic device includes a flexible substrate, a circuit substrate, and a battery pack including a conductor portion. The battery pack includes a battery that supplies power to the circuit substrate and includes a main surface and a side surface. The flexible substrate includes a radiating conductor. The flexible substrate includes bent portions at a central portion in the direction in which a transmission line extends so that the flexible substrate faces the side surface. The radiating conductor overlaps the conductor portion of the main surface of the battery pack in plan view.

Abstract: A transmission line includes a first interlayer connection conductor connecting a first signal conductor and a first mounting electrode, a second interlayer connection conductor connecting a second signal conductor and a second mounting electrode, a third and fourth interlayer connection conductors respectively including third and fourth interlayer connection conductors, and each connecting first and second ground conductors between the first and second signal conductors.

Abstract: An antenna installation structure includes an antenna substrate, an insulation layer, and a bonding material. The antenna substrate includes a dielectric base including a first main surface and a second main surface, and an antenna conductor and a ground conductor which are on the first main surface and are separated from each other. The insulation layer is in contact with the first main surface of the antenna substrate. The bonding material is between the insulation layer and a radiation side wall of a housing and is in contact with the insulation layer and the radiation side wall. The porosity of the insulation layer is lower than the porosity of the bonding material.

Abstract: An antenna installation structure includes an antenna substrate, an insulation layer, and a bonding material. The antenna substrate includes a dielectric base including first and second main surfaces, and an antenna conductor on the first main surface. The insulation layer is on the first main surface of the antenna substrate. The bonding material is between the insulation layer and a radiation side wall of a housing, is cured, and bonds the insulation layer to the radiation side wall. A linear expansion coefficient of the insulation layer is lower than a linear expansion coefficient of the bonding material and higher than a linear expansion coefficient of the antenna substrate.

Abstract: In a multilayer board, a transmission line includes layers including a first insulator layer, a first joining material layer in contact with a first surface of the first insulator layer, and a second joining material layer in contact with a second surface of the first insulator layer. A signal conductor of the transmission line is on the first surface of the first insulator layer, a relative permittivity of the second joining material layer is lower than a relative permittivity of the first joining material layer, and an adhesion strength between the first insulator layer and the first joining material layer is higher than an adhesion strength between the first insulator layer and the second joining material layer.

Abstract: A multilayered substrate includes first, second, and third insulating layers, and a transmission line. The first insulating layer includes first and second surfaces opposite to each other. A signal conductor of the transmission line is on the first surface of the first insulating layer. The second insulating layer is in contact with the first surface of the first insulating layer. The third insulating layer is in contact with the second surface of the first insulating layer. A dielectric loss of the second insulating layer is lower than a dielectric loss of the third insulating layer. A degree of close contact between the first insulating layer and the third insulating layer is higher than a degree of close contact between the first insulating layer and the second insulating layer.

Abstract: A transmission line includes a ground conductor between first and second signal conductors. A substrate includes a first insulating layer and a second insulating layer having a relative permittivity lower than a relative permittivity of the first insulating layer. The first and second insulating layers are laminated in the thickness direction of the substrate and in contact with each other. The first and second signal conductors and the ground conductor are on an interface at which the first and second insulating layers are in contact with each other. The first and second signal conductors and the ground conductor each include a surface in contact with the first insulating layer and a surface in contact with the second insulating layer, the surface in contact with the second insulating layer being larger than the surface in contact with the first insulating layer.

Abstract: A circuit board includes a first circuit board portion and a second circuit board portion. The first circuit board portion is provided with a first transmission line for a low-frequency signal or a low-speed signal, and the second circuit board portion is provided with a second transmission line for a high-frequency signal or a high-speed signal. The second circuit board portion is located on the first circuit board portion in a positional relationship in which the first transmission line and the second transmission line are side-by-side with each other. With this structure, signal leakage and interference between different signals are reduced or prevented in a line that transmits signals with different frequencies and different transmission speeds.

Abstract: An antenna unit includes a substrate, a body that includes a first conductive portion and a second conductive portion opposed to each other on side surfaces orthogonal or substantially orthogonal to a first main surface of the substrate, and first and second coil antennas the winding axes of which are orthogonal or substantially orthogonal to the first main surface. In a plan view of the first main surface, the first coil antenna is positioned in proximity to the first conductive portion, compared with the second coil antenna, and the second coil antenna is positioned in proximity to the second conductive portion, compared with the first coil antenna. In a plan view of the first main surface, a straight line passing through the first coil antenna and the second coil antenna intersects with the first conductive portion and the second conductive portion.

Abstract: An antenna element includes a multilayer body and a coil conductor. The multilayer body includes a first non-magnetic portion and a first magnetic portion laminated together. The first magnetic portion is closer to a first principal surface than is the first non-magnetic portion. The coil conductor includes a first conductor pattern portion and a first insulating pattern portion. The first conductor pattern portion is disposed between the first non-magnetic portion and the first magnetic portion. The first insulating pattern portion is provided on the first conductor pattern portion at a side facing the second principal surface, and has a line width less than a line width of the first conductor pattern portion. The first insulating pattern portion overlaps the first conductor pattern portion in plan view as viewed in a lamination direction of the multilayer body.

Abstract: An antenna device includes first and second coil antennas with winding axis directions that are not perpendicular to each other, and a feeder coil including a winding axis that extends perpendicular or substantially perpendicular to the winding axis of the first coil antenna. The feeder coil is located between the first and second coil antennas in the winding axis direction thereof. A first coil aperture is closer to a coil aperture of the first coil antenna than a second coil aperture. The second coil aperture is closer to a coil aperture of the second coil antenna than the first coil aperture. The first and second coil antennas are connected to each other in a polarity such that magnetic fluxes thereof with respect to the winding axis direction of the first coil antenna are in phase with each other.

Abstract: An antenna device includes a wiring board, a conductive member including a first conductor portion and a second conductor portion electrically connected to each other, a coil element including a coupling coil to be connected to a feed circuit, and a capacitor. The first conductor portion includes a conductor opening and a gap that connects the conductor opening and an outer edge of the first conductor portion, and the capacitor crosses the gap. The second conductor portion is connected to two points of an inner edge of the conductor opening, and, together with a portion of the first conductor portion and the capacitor, defines a loop-shaped current path. The coupling coil is magnetically coupled to the loop-shaped current path.

Abstract: An antenna device includes an insulating substrate, a coil antenna including a helically wound coil conductor and at least two mounting electrodes conducted to the coil conductor, and a wiring conductor disposed on the substrate and including connection portions connected to the mounting electrodes of the coil antenna. The wiring conductor includes a first wiring conductor parallel extending portion and a second wiring conductor parallel extending portion, and directions of currents flowing through the first wiring conductor parallel extending portion and the second wiring conductor parallel extending portion are opposite to each other with respect to a direction of a current flowing through the coil conductor.

Abstract: An antenna device includes a wiring board, a conductive member including a first conductor portion and a second conductor portion electrically connected to each other, a coil element including a coupling coil to be connected to a feed circuit, and a capacitor. The first conductor portion includes a conductor opening and a gap that connects the conductor opening and an outer edge of the first conductor portion, and the capacitor crosses the gap. The second conductor portion is connected to two points of an inner edge of the conductor opening, and, together with a portion of the first conductor portion and the capacitor, defines a loop-shaped current path. The coupling coil is magnetically coupled to the loop-shaped current path.

Abstract: An antenna device includes a first planar conductor, a second planar conductor that opposes the first planar conductor in a parallel or substantially parallel arrangement, and a coil element with a winding axis that extends in a direction parallel or substantially parallel to the first planar conductor and the second planar conductor, and includes a first coil opening end and a second coil opening end that opposes the first coil opening end. The first planar conductor includes a conductor outer edge, and a conductor opening including a portion that is continuous with the conductor outer edge. At least a portion of the conductor opening is positioned inside a conductor overlapping region. The first coil opening end of the coil element does not overlap the second planar conductor, and the second coil opening end of the coil element overlaps the conductor opening and the second planar conductor.