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 first signal conductor pattern, a first ground conductor pattern, and a second ground conductor pattern define a first transmission line with a strip line structure. A second signal conductor pattern, a third ground conductor pattern, and a fourth ground conductor pattern define a second transmission line with a strip line structure. A first connecting portion at an end of the first transmission line and a second connecting portion at an end of the second transmission line are stacked together so that the first ground conductor pattern is electrically connected to the third ground conductor pattern, the second ground conductor pattern is electrically connected to the fourth ground conductor pattern, and the first signal conductor pattern is electrically connected to the second signal conductor pattern.

A transmission line includes, in a stacked insulator in which insulator layers are stacked, a first transmission line portion including a first ground conductor pattern, a second ground conductor pattern, and a first signal conductor pattern, and a second transmission line portion including a third ground conductor pattern, a fourth ground conductor pattern, and a second signal conductor pattern. The first signal conductor pattern extends along the second signal conductor pattern. The first ground conductor pattern and the third ground conductor pattern are provided on different insulator layers and at least partially overlap each other in a plan view.

An electronic device includes a high-frequency transmission line member and a housing. The high-frequency transmission line member includes a flexible substrate, a signal conductor, and a ground conductor along the signal conductor. The housing is defined by a member separate from the high-frequency transmission line member and located at one principal surface side of the high-frequency transmission line member. The high-frequency transmission line member includes a first portion along the housing to face the housing, and a second portion spaced apart from the housing more than the first portion. The ground conductor is not provided at one principal surface side of the signal conductor in the first portion and is provided at least in the second portion.

A flat cable includes a plurality of resin layers that are flexible and stacked together, a line conductor, and grounding conductors. The flat cable includes a triplate line in which both surfaces of the line conductor oppose the corresponding grounding conductors, and a microstrip line in which only one of the surfaces of the line conductor opposes the corresponding grounding conductor. A width of the line conductor in the microstrip line is greater than a width of the line conductor in the triplate line, and the flat cable is bent at a position where the microstrip line is provided.

A multi-wire wiring board including insulation-coated wires each including a wire and a wire coating layer, and a wire-laying adhesive sheet on which the insulation-coated wires are wire-laid, in which the multi-wire wiring board includes a wire-laying adhesive sheet on which a high-frequency-compatible wire is disposed, the high-frequency-compatible wire including the wire coating layer being a low-dielectric resin having a relative permittivity less than 3.6 at 10 GHz, and a wire-laying adhesive sheet on which a general wire is disposed, the general wire including the wire coating layer being a general resin having a relative permittivity of 3.6 or more at 10 GHz.

An example circuit board structure includes: a substrate; and vias that are electrically conductive and that pass through the substrate to enable electrical connection through the circuit board structure. The substrate is thinner, and lengths of the vias are shorter, in first areas of the circuit board structure that deliver first speed signals than in second areas of the circuit board structure that deliver second speed signals and power. The first speed signals have a shorter rise time than the second speed signals.

A high-frequency signal line includes a dielectric body including a first dielectric layer and one or more other dielectric layers laminated together. A first signal line is provided on a first main surface, which is a main surface located on one side in a direction of lamination, of the first dielectric layer. A second signal line is provided on a second main surface, which is a main surface located on another side in the lamination direction, of the first dielectric layer so as to face the first signal line via the first dielectric layer. The second signal line is electrically connected to the first signal line. A first ground conductor is located on one side in the lamination direction than the first signal line. A second ground conductor is located on another side in the lamination direction than the second signal line.

In a high frequency filter, a multilayer structure includes a plurality of insulator layers, a first transmission line transmits an input signal, and a second transmission line is electromagnetic coupled with the first transmission line on the same insulator layer and transmits an output signal. A conductor layer defines capacitors with the first transmission line and the second transmission line with the insulator layer in between. A dielectric constant of the insulator layer that comes in contact with the first transmission line and the second transmission line is higher than a dielectric constant of an insulator layer other than the insulator layer.