A method for manufacturing a flexible circuit board capable of transmitting high frequency signals with reduced attenuation includes providing an inner wiring board including a first conductive wiring layer and a first substrate layer, the first conductive wiring layer including a signal line and two ground lines on both sides of the signal line, the first substrate layer covering a side of the first conductive wiring layer and defining first through holes which expose the signal line; providing two copper clad laminates including a second substrate layer and a copper foil, the second substrate layer having second through hole aligned with the first through holes; laminating the two copper clad laminates onto two sides of the inner wiring board via two adhesive layers, each adhesive layer defining third through holes aligned with the first and second through holes; and forming a second conductive wiring layer from the copper foil.

The concepts, systems, circuits and techniques described herein are directed toward a spiral antenna which may be provided using additive manufacturing technology so as to provide an antenna capable of operation at frequencies which are higher than spiral antennas manufactured using standard photo-etch or printed circuit board (PCB) manufacturing processes.

A circuit board includes a multilayer body including a main surface, a mounted conductor, and a signal conductor at an intermediate position in the lamination direction of the multilayer body, and a ground conductor on the main surface. The multilayer body includes a connection portion including a portion overlapping the mounted conductor and overlapping an external board joined via a conductive joint material through use of the mounted conductor, and a circuit portion. A first region, which is the region of a circuit portion of the ground conductor, includes opening holes and a second region, which is the region of a connection portion of the ground conductor, includes opening holes. The ratio of the opening area of the opening holes to that of the second region is larger than the ratio of the opening area of the opening holes to that of the first region.

An apparatus is disclosed comprising first printed circuit board—PCB—and second PCB structure each having a first surface and a second surface and a layer of electrically conductive material on the first surface thereof and being attached to each other in a substantially parallel configuration. A stripline is positioned between the two PCBs. Each one of the first PCB and the second PCB has a plurality of via-holes that are electrically conductive and are connected at one end to the layer of electrically conductive material on the first surface and to an electrically conductive pad on the second surface of the PCB. At least a first electrically conductive pad associated with the first PCB is located in proximity with a first electrically conductive pad associated with the second PCB thereby forming a capacitive configuration.

A circuit board includes a first layer, a second layer, a third layer, a plurality of plating through holes, at least one first intermediate layer and at least one second intermediate layer. The first layer and the second layer are used as reference voltage planes. A plurality of transmission wires are disposed on the third layer. The transmission wires are coupled to a wireless signal transceiver and a plurality of antenna arrays; wherein the third layer is disposed between the first layer and the second layer. The plating through holes are disposed at sides of the third layer, wherein the plurality of plating through holes are configured to connect the first reference voltage plane with the second reference voltage plane. The first intermediate layer is disposed between the first layer and the third layer, and the second intermediate layer is disposed between the second layer and the third layer.

A transmission line board includes an insulating substrate including a first principal surface, first and second signal lines, first and second signal electrodes, which are provided at the insulating substrate. The first signal electrode is connected to the first signal line, and is connected by capacitive coupling to a different circuit board. The second signal electrode is connected to the second signal line, and is connected to the different circuit board via a conductive binder. The first signal line is provided to transmit a signal in a first frequency band, and the second signal line is provided to transmit a signal in a second frequency band lower than the first frequency band.

A printed wiring board includes resin insulating layers, and conductor layers including a conductor layer such that the conductor layer includes a conductor circuit and that the conductor circuit has a surface index X/Y in a range of 1.00 to 2.20 where X is a length of an outer circumference of cross section of the conductor circuit, and Y is a length of an outer circumference of a reference quadrangle in the cross section of the conductor circuit. The reference quadrangle has a first reference line drawn with reference to bottom of deepest recess on first side, a second reference line is drawn with reference to bottom of deepest recess on second side, a third reference line is drawn with reference to bottom of deepest recess on third side, and a fourth reference line is drawn with reference to bottom of deepest recess on fourth side of the outer circumference.

A printed wiring board includes resin insulating layers, and conductor layers laminated on the resin insulating layers, respectively. The conductor layers includes a conductor layer including a conductor circuit formed such that the conductor circuit has recesses each having a depth of 2.0 μm or more and a bottom whose diameter is larger than a diameter of an opening part of a respective one of the recesses.

A device that includes a first board, a second board, and coaxial cable coupled to the first board and the second board. The coaxial cable includes a multi-line coaxial cable configured to provide at least two electrical paths for electrical currents between the first board and the second board. A first plug is coupled to the first board. A second plug is coupled to the second board. The coaxial cable includes a first receptable and a second receptable. The first receptable is configured to couple to the first plug. The second receptable is configured to couple to the second plug. The coaxial cable is configured to provide (i) a first electrical path for a first electrical current between the first board and the second board, and (ii) a second electrical path for a second electrical current between the first board and the second board.

In some aspects, a flexible cable may comprise: a flexible strip with first and second parallel surfaces and first and second ends, said flexible strip being electrically insulating; a metal stripline within said flexible strip; first and second metallic grounding planes on said first and second surfaces, respectively; and a first circuit board mechanically attached to at least one of said first end of said flexible strip and said first and second metallic grounding planes at said first end, said first circuit board being mechanically stiff, said metal stripline being electrically connected to electrical circuitry on said first circuit board.