An aspect of the present invention reduces loss that may occur in cases where electromagnetic waves are guided from one main surface side of a substrate to the other main surface side of the substrate. A waveguide device (10, 10A, 20) includes: a substrate (11); a first conductor layer (12A) and a second conductor layer (12B) which are provided on both main surfaces of the substrate, respectively; a main conductor post (MP) which penetrates between the both main surfaces; and one or more sub-conductor posts (SP) which penetrate between the both main surfaces and which, together with the main conductor post, guide a TEM mode or a quasi-TEM mode.

A circuit board includes an insulation layer, a signal line formed over the insulation layer and extending in a direction X, and a conductor layer formed under the insulation layer. The insulation layer has periodic dielectric-constant distribution in a direction Y orthogonal to the direction X. The conductor layer includes a slit at a position corresponding to the signal line. The slit expands an electric field produced between the signal line and the conductor layer; causes less difference in dielectric constants of the insulation layer in the vicinity of the signal line (the difference is caused by the positional relationship between the signal line and the dielectric-constant distribution of the insulation layer); and reduces difference in signal transmission speeds caused by the positional relationship.

A transmission line portion of a flat cable includes first regions and second regions connected alternately. In the first region, the transmission line portion is a flexible tri-plate transmission line including a dielectric element including a signal conductor, a first ground conductor including opening portions, and a second ground conductor which is a solidly filled conductor. In the second region, the transmission line portion is a hard tri-plate transmission line including a wide dielectric element including a meandering conductor, and a first ground conductor and a second ground conductor which are solidly filled conductors. A variation width of the characteristic impedance in the second region is larger than a variation width of the characteristic impedance in the first region.

An interconnect topology that includes vertical trench routing in a substrate is disclosed. In one embodiment, the interconnect comprises a substrate having a plurality of layers including a first ground plane layer; a pair of signal conductors that form a differential signal pair, each conductor of the pair of signal conductors having a first portion and a second portion, the second portion extending from the first portion into at least one of the plurality of layers, wherein width of the second portion is less than width of the first portion; and wherein the first ground plane layer is only a first partial layer and has a first void region that is closer to the pair of signal conductors than the first partial layer.

A method for fabricating microstrip line structure is disclosed. First, a substrate is provided, ground patterns are formed on the substrate, an interlayer dielectric (ILD) layer is formed on the ground patterns, contact plugs are formed in the ILD layer, a ground plate is formed on the ILD layer, and a signal line is formed on the ground plate. Preferably, the ground plate includes openings that are completely shielded by the ground patterns.

A transmission line impedance transformer including at least two different dielectric media having different dielectric properties, each of the dielectric media being configured to taper in thickness along the length of the impedance transformer in an inverse relationship with respect to each other so as to form a combined dielectric medium having an effective dielectric property that is graded along the transmission path. The two or more dielectric media may be disposed between two conductors to provide an impedance transformer in which a characteristic impedance of the transmission line varies along its length in response to the gradation of the effective dielectric property of the combined dielectric medium.

A downhole energy transmission system is described. The system can include a casing string having a number of casing pipe disposed within a wellbore, where the casing string has at least one wall forming a cavity. The system can also include a remote electrical device disposed within the cavity of the casing string at a first location. The system can further include a first stripline cable disposed on an outer surface of the casing string, where the first stripline cable transmits a first energy received from an energy source. The system can also include a second stripline cable disposed adjacent to the first stripline cable at the first location, where the second stripline cable is electrically coupled to the remote electrical device.

A substrate integrated coaxial line (SICL) array is proposed in this invention. The SICL array includes at least a single channel. The inner conductor is between the first outer conductor layer and the second outer conductor layer. The first dielectric layer is between the first outer conductor layer and the inner conductor layer. The second dielectric layer is between the inner conductor layer and the second outer conductor layer. The metal vias columns are across the structure in vertical direction. The first outer conductor layer, the second outer conductor layer and the metal vias columns form the outer conductor. Many single channels in horizontal and vertical directions form the array, and adjacent channels share outer conductors. Vertically adjacent channels share outer conductor layers, and horizontally adjacent channels share metal vias. The SICL array can be used as board level/package level/chip level interconnects.

A high-frequency signal transmission line includes an element, a linear signal line provided at the element and including a first end and a second end, and at least one ground conductor provided at the element and extending along the signal line. The element includes stacked insulating layers. The ground conductor is positioned opposite to the signal line with the insulating layer positioned therebetween. The ground conductor is a contiguous conductor. The signal line, the ground conductor, and the element generate a characteristic impedance. The signal line includes a first section and a second section. The first section is an uninterrupted section generating a characteristic impedance greater than or equal to a first characteristic impedance at the first end and including the first end. The second section generates a characteristic impedance less than the first characteristic impedance and is adjacent to the first section. The second section is longer than the first section. The signal line is wider in the second section than in the first section.

A transmission line includes a first structure including a first insulating substrate and a ground conductor on the first insulating substrate, a second structure including a second insulating substrate and a signal line, ground conductors, and interlayer connection conductors on or in the second insulating substrate, a third insulating substrate including openings, and metal bonding materials that bond the structure and the structure to each other with the third insulating substrate interposed therebetween. The first and second insulating substrates are stacked with the third insulating substrate interposed therebetween to define hollow portions. The signal line and the ground conductor partially face each other across the hollow portions in a bonding direction. The ground conductor includes openings in regions that overlap the signal line but do not overlap the hollow portions when looking in plan view in the bonding direction.