An aspect of the present disclosure is directed to and provides radar-reflecting systems and apparatus that employ metasurfaces to produce enhanced radar cross sections that are greater than those produced by the geometry of the surfaces alone. Another aspect of the present disclosure is directed to and provides heat-ducting systems and apparatus that include metasurfaces. A further aspect of the present disclosure is directed to and provides cards with metasurfaces. Exemplary embodiments utilize fractal plasmonic surfaces for a metasurface.

Base station antennas include an externally accessible active antenna module releasably coupled to a recessed segment that is over a chamber in the base station antenna and that is longitudinally and laterally extending along and across a rear of a base station antenna housing. The base station antenna housing has a passive antenna assembly that cooperates with the active antenna module.

An antenna structure includes a substrate, a plurality of reflective plates, a grounding plate, a radiating member, a signal feeding via and a plurality of conductive vias. The substrate has opposite first and second surfaces and comprises liquid crystal polymer. The reflective plates are arrayed on the first surface of the substrate. The grounding plate is disposed on the second surface of the substrate and overlapped with the reflective plates in a normal direction of the substrate. The grounding plate further includes an opening. The radiating member is disposed on the first surface of the substrate and physically separated from the reflective plates. The signal feeding via is coupled with the radiating member and penetrates through the substrate to be exposed in the opening of the grounding plate. The conductive vias penetrate through the substrate and respectively connect the reflective plates and the grounding plate.

An antenna structure includes a substrate, a plurality of reflective plates, a grounding plate, a radiating member, a signal feeding via and a plurality of conductive vias. The substrate has opposite first and second surfaces and comprises liquid crystal polymer. The reflective plates are arrayed on the first surface of the substrate. The grounding plate is disposed on the second surface of the substrate and overlapped with the reflective plates in a normal direction of the substrate. The grounding plate further includes an opening. The radiating member is disposed on the first surface of the substrate and physically separated from the reflective plates. The signal feeding via is coupled with the radiating member and penetrates through the substrate to be exposed in the opening of the grounding plate. The conductive vias penetrate through the substrate and respectively connect the reflective plates and the grounding plate.

To accurately estimate frequency characteristics from structural parameters of a frequency selective surface. A frequency selective surface design apparatus includes an LC generation unit 20 that receives an input of a structural parameter, and generates an inductance L and a capacitance C of a unit cell, a corrected resonance point calculation unit 30 that receives the number n of times of calculation input from an outside, the inductance L, and the capacitance C, models a correction circuit by using a circuit in which a virtual capacitance is connected in parallel via a transmission line to each distribution inductance obtained by division of the inductance L by the calculation number n and the transmission line is terminated at the capacitance C, and calculates a corrected resonant frequency fC from the impedance of the correction circuit, and a characteristic calculation unit 40 that receives inputs of the inductance L, the capacitance C, and the corrected resonant frequency fC, calculates a pre-correction resonant frequency from the inductance L and the capacitance C, obtains a correction coefficient by dividing the corrected resonant frequency fC by the pre-correction resonant frequency, and calculates a corrected return loss and a corrected insertion loss.

An antenna is installed on an installation surface of a wheel. The antenna includes a first conductor, a second conductor, one or more third conductors, a fourth conductor, and a feeding line. The first conductor and the second conductor face each other in a first axis. The one or more third conductors are located between the first conductor and the second conductor and extend in the first axis. The fourth conductor is connected to the first conductor and the second conductor and extends in the first axis. The feeding line is electromagnetically connected to the third conductor. The first conductor and the second conductor are capacitively connected via the third conductor. A surface of the fourth conductor faces the installation surface of the wheel in a second axis perpendicular to the first axis.

An antenna is installed on an installation surface of a wheel. The antenna includes a first conductor, a second conductor, one or more third conductors, a fourth conductor, and a feeding line. The first conductor and the second conductor face each other in a first axis. The one or more third conductors are located between the first conductor and the second conductor and extend in the first axis. The fourth conductor is connected to the first conductor and the second conductor and extends in the first axis. The feeding line is electromagnetically connected to the third conductor. The first conductor and the second conductor are capacitively connected via the third conductor. A surface of the fourth conductor faces the installation surface of the wheel in a second axis perpendicular to the first axis.

In one embodiment of the present disclosure, an antenna assembly includes a patch antenna array including an upper patch antenna layer, a lower patch antenna layer, and a spacer therebetween, wherein the spacer includes a plurality of apertures defined by cell walls, wherein the each aperture aligns with an upper patch antenna element and a lower patent antenna element from the patch antenna array.

A test apparatus includes a test antenna that is provided in an OTA chamber 50 and transmits or receives a radio signal to or from an antenna 110 of a DUT 100, and a measurement device that measures transmission characteristics or reception characteristics of the DUT 100 disposed in a quiet zone QZ, by using the test antenna. The test antenna includes a reflector reflection type test antenna 6a that transmits or receives a radio signal to or from the antenna 110 of the DUT via a reflector 7, and mirror reflection type test antennae 6b, 6c, 6d, 6e, and 6f that transmits or receives a radio signal to or from the antenna 110 of the DUT via mirrors 9b to 9f.

The invention relates to a wire antenna suitable for operating in at least one frequency band, including a plurality of stacked layers, including at least one radiating element placed on a support layer, said support layer being placed on a spacing substrate placed on a reflective plane, characterised in that it includes at least one resistive grille having a resistive surface with predetermined resistance, including at least one set of repetitive, non-contiguous empty patterns, said grille being placed between the spacing substrate and the reflective plane.