A multilayer substrate includes layers stacked on each other in an up-down direction of a multilayer body. The layers include a first spacer, a first ground conductive layer above the first spacer, and a signal conductive layer that overlaps the first ground conductive layer and is located below the first spacer. First through-holes pass through the first spacer and are arranged along a first direction. A distance between centroids of first through-holes adjacent to each other in the first direction is uniform or substantially uniform. Sets of first through-holes are provided in the first spacer. Sets of first through-holes are arranged along a second direction. A distance between centroids of first through-holes adjacent to each other in the second direction is uniform or substantially uniform. At least one first through-hole is a first hollow through-hole overlapping the signal conductive layer.

A dielectric substrate for RF, microwave, or millimeter wave devices, circuits, or surfaces includes a propagating region for transmitting or reflecting an electromagnetic field, and one or more material-filled vias located within the propagating region. The application of an external electric or magnetic field to the material-filled vias may be used to tune the electric permittivity or the magnetic permeability of the fill material and hence control the effective electric permittivity or the effective magnetic permeability of the dielectric substrate within the propagating region. A dimension of the material-filled vias may be less than half of a wavelength of the propagating electromagnetic field. The fill material may include liquid crystals, a ferroelectric crystal composite, a ferromagnetic crystal composite, organic semiconductors, and/or electro-optic or magneto-optic polymers.

An object is to provide a transmission line having an air bridge structure in which grounding conductors of a transmission line are connected by wiring and which is stable in terms of mechanical strength by lowering an electrostatic capacitance in a region where the wirings connecting the central conductor and the grounding conductor intersect with each other. The transmission line includes a substrate, a first central conductor and a second central conductor that are formed on a surface of the substrate, a third central conductor that has a first erection portion and a second erection portion erected on the surface, and a first grounding conductor and a second grounding conductor. The transmission line further includes a third grounding conductor connecting the first grounding conductor and the second grounding conductor. The third central conductor and the third grounding conductor form an air bridge structure.

A film transmission line according to an embodiment of the present invention includes a dielectric layer, and an electrode line disposed on the dielectric layer. The electrode line has an effective efficiency of 200%/μm or more at a frequency of 5 GHz or more. The film transmission line may be applied to a high frequency thinned antenna and an image display device.

In a described example, an apparatus includes: a package substrate having a device side surface and a board side surface opposite the device side surface; a physics cell mounted on the device side surface having a first end and a second end; a first opening extending through the package substrate and lined with a conductor, aligned with the first end; a second opening extending through the package substrate and lined with the conductor, aligned with the second end; a millimeter wave transmitter module on the board side, having a millimeter wave transfer structure including a transmission line coupled to an antenna aligned with the first opening; and a millimeter wave receiver module mounted on the board side surface of the package substrate and having a millimeter wave transfer structure including a transmission line coupled to an antenna for receiving millimeter wave signals, aligned with the second opening.

In a transmission line, a hollow portion overlaps a first ground conductor layer in an up-down direction. In a first orthogonal direction, the hollow portion includes a first portion extending in a second orthogonal direction of a signal conductor layer. In the first portion, a portion at which a width of the first portion in the second orthogonal direction has a first portion maximum width value is a first portion maximum width portion. A portion at which the width of the first portion in the second orthogonal direction has a first portion minimum width value is a first portion minimum width portion. A portion at which the width of the first portion in the second orthogonal direction has a first portion intermediate width value is a first portion intermediate width portion located between the first portion maximum width portion and the first portion minimum width portion in the front-back direction.

A coplanar waveguide transmission line and a design method thereof are provided. The coplanar waveguide transmission line includes a first dielectric substrate, a center conductor strip, and two ground conductor strips. The first dielectric substrate has a first surface and a second surface opposite to each other. The center conductor strip and the ground conductor strips are stacked and fixed to the first surface. The center conductor strip includes a first segment and a second segment. A width of the first segment is greater than a width of the second segment, so that the first segment and the second segment form a step structure. A rectangular groove recessed toward the second surface is defined in the first surface, and a part of the center conductor strip is stacked and fixed to a side, distal from the second surface, of the rectangular groove to form a defected ground structure.

A transmission line includes a signal conductor and one or more return conductors, one or more of which having a stepped multi-layer structure. The return conductors may be disposed at opposite sides of the signal conductor. The return conductors may be multi-layer structures. At least some layers of each return conductor may have a stepped arrangement that defines a curve, such as an exponential curve. Additionally or alternatively, the signal conductor may be a stepped multi-layer structure, where at least some layers of the signal conductor may define a curve, such as an exponential curve. The signal conductor may be disposed at one or more upper layers of the transmission line or may be embedded at one or more layers near the center of the transmission line.

Aspects of the present disclosure are directed to a photonic integrated circuit (PIC) having a resistivity-engineered substrate to suppress radio-frequency (RF) common-mode signals. In some embodiments, a semiconductor substrate is provided that comprises two portions having different levels of resistivity to provide both suppression of common mode signals, and reduction of RF absorption loss for non-common mode RF signals. In such embodiments, a bottom portion of the semiconductor substrate has a low resistivity to suppress common mode via RF absorption, while a top portion of the semiconductor substrate that is adjacent to conductors in the IC has a high resistivity to reduce RF loss.

Various substrate-integrated waveguide (SIW) filtering crossover systems are described. An example SIW filtering crossover system may include: a substrate; a top metal plate placed on top of the substrate; a bottom metal plate placed beneath the substrate; a plurality of metalized via-holes in the substrate connecting the top metal plate and the bottom metal plate; and a plurality of grounded-coplanar-waveguides (GCPWs) coupled to sidewalls of the crossover system, wherein each of the GCPWs connects the crossover system to a respective microstrip line for signal transmission between the respective microstrip line and the crossover system.