A radar-absorbing structure is disclosed which includes a fiber, at least one binding agent disposed on the fiber and thus enabling the fiber to bind to another fiber.

The present disclosure describes techniques for fabricating a textile article from a laminate formed by curing a reinforced fiber matrix and a resin substrate. The resin substrate may include iron oxide particles, such as iron oxide, Fe.sub.3O.sub.4, that are capable of absorbing and attenuating RF signals within a desired RF signal range, namely 0 GHz-3 GHz, 3 GHz, −8 GHz, and greater than or equal to 10 GHz. The iron oxide particles may include Fe.sub.3O.sub.4Fe, Fe.sub.3O.sub.4Ni, or Fe.sub.3O.sub.4, and/or so forth. Each iron oxide particle is selected based on the RF signal range that the textile article is intended to absorb. In other words, a change in iron oxide particle composition and proportion by volume may impact the RF signals absorbed and attenuated by the textile article.

The present disclosure describes a textile article for radio frequency (RF) absorption and attenuation. The textile includes a laminate that is formed via curing a wet laminate at room temperature for a cure time, the wet laminate comprising a resin substrate and a reinforced fiber matrix. The reinforced fiber matrix may include one of a bamboo fiber matrix, a cotton fiber matrix, a polyester fiber matrix, a nylon fiber matrix, or a wool fiber matrix. The resin substrate may include a first portion of iron oxide particles and a second portion of the elastic polymer solution, the first portion of iron oxide particles being based at least in part on an RF signal range that the textile article is configured to absorb and attenuate. For example, the iron oxide particles may include Fe.sub.3O.sub.4Fe, Fe.sub.3O.sub.4Ni, or Fe.sub.3O.sub.4, and/or so forth.

A method for controlling dielectric constant of a composite material through micro pattern printing includes setting a dielectric constant value needed in the composite material, preparing a paste having an electromagnetic loss material, fabricating a composite material sheet by forming the paste on one surface of a base member in a predetermined pattern, and fabricating the composite material sheet with the micro patterns including the electromagnetic loss material on the base member by drying the composite material sheet, wherein the base member is formed of a sheet and includes fibers.

A stealth antenna includes an electromagnetic wave absorbing structure and an antenna patch embedded in the electromagnetic wave absorbing structure. The electromagnetic wave absorbing structure includes an upper dielectric layer, a lower dielectric layer and a spacer disposed between the upper dielectric layer and the lower dielectric layer. The upper dielectric layer includes a dielectric fabric and a conductive coating layer combined with at least a portion of the dielectric fabric. The lower dielectric layer includes a dielectric fabric and has a dielectric constant lower than that of the upper dielectric layer. The antenna patch is disposed between the spacer and the lower dielectric layer.

Provided is an apparatus and method for radar calibration that utilizes external shielding structures to be constructed around the body frame of a system to manage external signature presence and block unwanted signal emissions and intrusions. The inventive structures can adapt to desired user requirements or to environmental change as needed. The variable shielding with isolating connectors to the body frame of the system allows for aerodynamic needs to be sustained due to the mesh design while also protecting against electromagnetic spectrum interference and electro-optical short wave and long wave infrared signature emissions. The shielding can also be formed to emit a known or desired radio frequency response based on geometric shapes in order to influence radar cross-section readings. Communication with external environment is completed through the use of the shielding as a series of antennas.

An active IR camouflage device may include a base layer, a first dielectric layer over the base layer, a phase transition material layer over the first dielectric layer, a second dielectric layer over the phase transition material layer, and a first metal layer over the second dielectric layer and defining a pattern of openings therein. The active IR camouflage device may have circuitry configured to selectively cause a transition from a first phase state to a second phase state of the phase transition material layer to control IR reflectance/emission of a top plasmonic layer, making it appear/disappear from the IR detector/camera. In some embodiments, the active IR camouflage device may also include a second metal layer between the base layer and the first dielectric layer.

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 antenna apparatus includes an electrically conductive section having peripheral edges, an antenna element coupled to the electrically conductive section, which transmits or receives electromagnetic signals, and an electromagnetic absorbing carbon material component. The carbon material component is generally disposed adjacent to the electrically conductive section, and includes a border region extending beyond the peripheral edges of the electrically conductive section. The carbon material component can be constructed of a carbon fiber fabric in which the carbon fibers are arranged to increase the effective signal to noise ratio of the antenna apparatus and enhance antenna performance without increasing the baseline power consumption level. The carbon fibers can be coated with silicone to insulate them externally while enhancing their lengthwise conductivity.

A radio wave absorber (la) includes a resistive layer (20), an electrical conductor (30), and a dielectric layer (10). The resistive layer (20) includes indium tin oxide as a main component. The electrical conductor (30) reflects a radio wave. The dielectric layer (10) is disposed between the resistive layer (20) and the electrical conductor (30) in the thickness direction of the resistive layer (20). The dielectric layer (10) is formed of a polymer. The content of tin oxide in the indium tin oxide included in the resistive layer (20) is more than 0 weight % and less than 20 weight %. The number of hydrogen atoms included in the resistive layer (20) is 5% or more of the total number of indium atoms, tin atoms, oxygen atoms, and hydrogen atoms included in the resistive layer (20).