A transmission line includes a substrate, a high-frequency signal transmission line, a differential signal transmission line, and a power supply line. The substrate is insulating, extends in a predetermined direction, and internally includes each of the high-frequency signal transmission line, the differential signal transmission line, and the power supply line. The power supply line and the high-frequency signal transmission line are in parallel or substantially in parallel to each other, and the differential signal transmission line is between the power supply line and the high-frequency signal transmission line.

Provided is a circuit structural body is formed into a shape including: A circuit structural body, including: a multilayer board, which includes a plurality of layers of a first to N-th tri-plate structural bodies each including a first to N-th (N is an integer of 2 or more) planar conductors; an interlayers connection conductor, which is configured to connect the first to N-th planar conductors to each other; and a side-surface ground conductor, which is formed on a side surface of the multilayer board, and is approximately parallel to and near the interlayers connection conductor.

A multi-antenna system includes an antenna part and a cable part. The antenna part includes comprising antenna lines forming antenna elements. The cable part includes a feeding lines for the antenna elements. Both the antenna part and the cable part are implemented using a flexible printed circuit board. The antenna part includes a single conductor layer area. The cable part includes a three conductor layer area.

A multilayer board includes a laminated insulating body, signal conductors inside the laminated insulating body and extending in a transmission direction, and ground conductors sandwiching each of the signal conductors in a lamination direction via the insulating base material layers. The multilayer board includes a parallel extending portion in which the signal conductors extend parallel and that includes signal conductors arranged separately from each other in a direction orthogonal to the transmission direction in a planar view in the lamination direction, and a signal conductor overlapping with the signal conductor in a planar view in the lamination direction and arranged separately from the signal conductor in the lamination direction. The parallel extending portion includes first and second regions arranged separately in a direction orthogonal to the transmission direction in a planar view in the lamination direction.

Disclosed is a low-loss and flexible transmission line-integrated multi-port antenna for an mmWave band. The multi-port antenna includes a plurality of antennas arranged on different substrate layers to form a multi port and a plurality of transmission lines corresponding to the plurality of antennas, respectively, in which central conductors used as signal lines of the transmission lines are integrated with corresponding electricity feeding portions of the antennas and arranged on different layers. Here, the antennas each include a dielectric substrate formed as a dielectric having a certain thickness on a ground plate, and a signal conversion portion formed on the dielectric substrate and configured to convert an electrical signal of a mobile communication terminal into an electromagnetic wave signal and radiate the electromagnetic wave signal into the air or to receive an electromagnetic wave signal in the air into an electrical signal of a mobile communication terminal.

A high frequency flexible flat cable includes a first metal isolation layer, a first low-k dielectric adhesive layer attached to one side of the first metal isolation layer, a second low-k dielectric adhesive layer attached another side of the first metal isolation layer and at least two conductor layers respectively attached to the first low-k dielectric adhesive layer and the second low-k dielectric adhesive layer. In addition, the high frequency flexible flat cable further includes a third low-k dielectric adhesive layer, a fourth low-k dielectric adhesive layer, a second metal isolation layer and a third metal isolation layer. The second metal isolation layer and the third metal isolation layer are respectively adhered to outsides of the conductor layers by using the third low-k dielectric adhesive layer and the fourth low-k dielectric adhesive layer to adjust the impedance of the high frequency flexible flat cable according to requirements.

A multilayer board includes a layered body including insulating base material layers that are laminated, and first and second signal lines, a first ground conductor including a first opening, a second ground conductor, a third ground conductor, and an interlayer connecting conductor. The first signal line overlaps the first opening when seen in a layering direction. The second signal line is provided on a layer different from a layer including the first signal line and includes a portion extending side by side with the first signal line when seen in the Z-axis direction. The first, second, and third ground conductors are connected by the interlayer connecting conductor. The third ground conductor is disposed on a layer including the first signal line or a layer positioned between the first signal line and the second signal line.

A transition structure for millimeter wave is provided. The transition structure includes a first layer signal element coupled to an end of a first transmission line and a plurality of first layer ground elements surrounding the end of the first transmission line equidistantly from the end of the first transmission line and disposed along two opposite sides of a strip body of the first transmission line equidistantly from the strip body of the first transmission line. The transition structure further includes an intermediate layer signal element coupled to the first layer signal element and a plurality of intermediate layer ground elements surrounding the intermediate layer signal element quasi-coaxially. A multilayer transition structure including a multilayer structure and the transition structure is also provided. Therefore, the problem of operating frequency caused by the thickness of the multilayer structure can be overcome, thereby increasing the resonance frequency of the multilayer structure.

An antennas-in-package (AiP) verification board is provided, which includes a carrier board configured for disposing an antenna array or an electronic circuit; and a plurality of SMPM connectors. The plurality of SMPM connectors are arranged in an array on the carrier board and electrically connected with the antenna array or the electronic circuit of the carrier board for testing the characteristics of the antenna array on the carrier board or the characteristics of the electronic circuit on the carrier board. The AiP verification board is fixed on a beamforming test platform. In addition to the aforementioned AiP verification board, an AiP verification board including a plurality of adaptor structures and an AiP verification board including a plurality of connectors and a plurality of adaptor structures are also provided.

Provided is a rapid over-the-air (OTA) production line test platform, including a device under test (DUT), an antenna array and two reflecting plates. The DUT has a beamforming function. The antenna array is arranged opposite to the DUT, and emits beams with beamforming. Two reflecting plates are disposed opposite to each other, and are arranged between the DUT and the antenna array. The beam OTA test of the DUT is carried out by propagation of the beams between the antenna array, the DUT and the two reflecting plates. Accordingly, the test time can be greatly shortened and the cost of test can be effectively reduced. In addition to the above-mentioned rapid OTA production line test platform, platforms for performing the OTA production line test by using horn antenna arrays together with bending waveguides and using a 3D elliptic curve are also provided.