A radio wave absorbing member 1a includes a radio wave absorber 10 and a support 20 having a sheet shape. The radio wave absorber 10 includes a resistive layer 12, a reflective layer 14, and a dielectric layer 13. The reflective layer 14 reflects a radio wave. The dielectric layer 13 is disposed between the resistive layer 12 and the reflective layer 14 in the thickness direction of the reflective layer 14. The support 20 supports the radio wave absorber 10. The support 20 includes a matrix resin 20m and a flame retardant 20p.

A radio wave absorber includes a resistive layer, an electroconductive layer, and a dielectric layer. The resistive layer has a first main surface with a plurality of first openings formed at equal intervals. The electroconductive layer has a second main surface with a plurality of second openings formed at equal intervals. The dielectric layer is disposed between the resistive layer and the electroconductive layer. In the radio wave absorber, a value obtained by dividing a larger value out of a first ratio and a second ratio by a smaller value out of the first ratio and the second ratio is 1.3 or more. The first ratio is a ratio (G.sub.R/W.sub.R) of a size G.sub.R of the first opening to a distance W.sub.R between the first openings. The second ratio is a ratio (G.sub.C/W.sub.C) of a size G.sub.C of the second opening to a distance W.sub.C between the second openings.

Various embodiments relate to an electromagnetic wave absorber having a honeycomb sandwich structure, which is capable of absorbing broadband electromagnetic waves using electromagnetic properties of a metal-coated dielectric fiber, may comprise: at least two honeycomb core layers in each of which hexagonal units formed of a material comprising the metal-coated dielectric fiber are continuously arranged; and skin layers which are disposed on top surfaces and bottom surfaces of the at least two honeycomb core layers and each include a bottom layer, a top layer, and an intermediate layer. Various other embodiments are possible.

An impedance matching film 10 includes a plurality of domains 11. Each of the domains 11 has a plurality of openings 12 having different shapes. The pluralities of openings 12 are periodically arranged in a specific direction along main surfaces 10f of the impedance matching film 10. Each of sizes of the domains 11 in the specific direction is 50 μm or more.

A radio frequency (RF) aperture includes an array of electrically conductive tapered projections arranged to define a curved aperture surface, such as a semi-cylinder aperture surface, or a cylinder aperture surface (which may be constructed as two semi-circular aperture surfaces mutually arranged to define the cylinder aperture surface). The RF aperture may further include a top array of electrically conductive tapered projections arranged to define a top aperture surface. The top aperture surface may be planar, and a cylinder axis of cylinder aperture surface may be perpendicular to the plane of the planar top aperture surface. The RF aperture may further include baluns mounted on at least one printed circuit board, each having a balanced port electrically connected with two neighboring electrically conductive tapered projections of the array and further having an unbalanced port.

The disclosure discloses a wide-frequency wave-absorbing metamaterial, which comprises a plurality of layers of substrates and microstructures respectively arranged on the substrates at different layers. The wave-absorbing frequency band of the wide-frequency wave-absorbing metamaterial is relatively wide. The disclosure further discloses an electronic device and a method for obtaining a wide-frequency wave-absorbing metamaterial. By using the foregoing manner, the disclosure can enable a wave-absorbing metamaterial to significantly increase a wave-absorbing bandwidth based on a relatively good electromagnetic wave absorbing effect.

In one embodiment, an antenna system includes a device for attenuating undesirable radiation from an antenna. The device includes a perimeter plate adapted to be located around the perimeter of the antenna. The perimeter plate has one or more concentric perimeter bands, where each perimeter band comprises an array of distinct EM-field-suppressing features. The surface of each suppressing features is metallic. The dimensions, arrangement, and number of the suppressing features are such that the features form a meta-material and the perimeter plate attenuates back-lobe and/or side-lobe radiation generated by the antenna.

The present invention relates to a mechanical meta-material based electromagnetic wave absorber, wherein a shape of the electromagnetic wave absorber is any one of a kelvin-foam, an octet-truss, a body-centered cubic lattice, a simple cubic triply minimal surface (SC-TPMS), and a cubic cellular core (CCC) and a honeycomb, a dielectric loss of the electromagnetic wave absorber is controlled by changing a strut diameter of a unit cell including at least one of carbon black, carbon nanotube, carbon fiber and graphene constituting the electromagnetic wave absorber.

An electromagnetic wave absorber (1a) includes a resistive layer (10), an electrically conductive layer (20) and a dielectric layer (30). The electrically conductive layer (20) has a sheet resistance lower than a sheet resistance of the resistive layer (10). The dielectric layer (30) is disposed between the resistive layer (10) and the electrically conductive layer (20). The electromagnetic wave absorber (1a) has a first slit (15). The first slit (15) extends, in the resistive layer (10), from a first principal surface (10a) distal to the dielectric layer (30) toward the dielectric layer (30) in a direction perpendicular to the first principal surface (10a) and divides the resistive layer (10) into a plurality of first blocks (17). Each of the first blocks (17) has a minimum dimension (D1) of 2 mm or more at the first principal surface (10a).

A low profile array (LPA) includes an antenna element array layer having at least one Faraday wall, and a beamformer circuit layer coupled to the antenna element array layer. The beamformer circuit layer has at least one Faraday wall. The Faraday walls extends between ground planes associated with at least one of the antenna element array layer and the beamformer circuit layer.