There is provided a radio wave absorbing composition containing a magnetic powder and a binder. There is also provided a radio wave absorber containing a magnetic powder and a binder. The magnetic powder is a powder of a substitution-type hexagonal ferrite subjected to surface treatment with a surface treatment agent, the surface treatment agent is a silicon-based compound, and the binder is an olefin-based resin.

An antenna device that includes a first antenna configured to perform communication using a predetermined frequency band, and a second antenna configured to perform communication using the predetermined frequency band, and the first antenna and the second antenna are arranged such that amplitude directions of radio waves which are output from the first antenna and the second antenna coincide with each other.

RF-absorber assemblies for assisting PIM hunting at cellular base station antennas. An RF-absorber panel section includes a non-absorbing spacer layer adjacent to an antenna under evaluation. An RF-absorbing layer is positioned adjacent to the non-absorbing spacer layer. A low-PIM RF-shield layer is positioned adjacent to the RF-absorbing layer, so that the RF-absorbing layer is positioned between the RF-shield layer and the non-absorbing spacer layer. RF-absorber panel assembly kits include RF-absorber panel sections that removably attach to each other and to an assembly cover, which removably attaches over a panel antenna. A cylindrical assembly for a multi-directional antennas includes tapered RF-absorber sections within a cylindrical RF-absorber. An iris allows directional PIM hunting with the cylindrical RF-absorber. A PIM hunting procedure utilizes a full-perimeter RF panel assembly for directional PIM hunting. A directional RF-absorber panel assembly includes front and rear RF-absorber panel assemblies and lateral RF-shield blankets.

A tile for reducing a radar wave reflection from a surface, the tile being a flexible surface sheet which is adhesively attachable to the surface, wherein the flexible surface sheet reduces the radar wave reflection from the surface at a frequency, the frequency being a frequency between 1 GHz and 12 GHz; and, wherein the flexible surface sheet is a laminate of layers, wherein at least one of a top surface and a bottom surface of the flexible surface sheet is adapted to be adhesively attachable to the surface, and wherein the laminate of layers comprises: a first layer comprising a polymer matrix into which a particulate filler is dispersed, wherein the particulate filler has radar absorbing properties; a second layer comprising a polymer matrix, the second layer adjoining the first layer, wherein the polymer matrix of at least one of the first and the second layer is thermoplastic polyurethane.

A tile for reducing a radar wave reflection from a surface, the tile being a flexible surface sheet which is adhesively attachable to the surface, wherein the flexible surface sheet reduces the radar wave reflection from the surface at a frequency, the frequency being a frequency between 1 GHz and 12 GHz; and, wherein the flexible surface sheet is a laminate of layers, wherein at least one of a top surface and a bottom surface of the flexible surface sheet is adapted to be adhesively attachable to the surface, and wherein the laminate of layers comprises: a first layer comprising a polymer matrix into which a particulate filler is dispersed, wherein the particulate filler has radar absorbing properties; a second layer comprising a polymer matrix, the second layer adjoining the first layer, wherein the polymer matrix of at least one of the first and the second layer is thermoplastic polyurethane.

An antenna module is provided. According to an aspect of the present disclosure, an antenna module attached to a support surface provided in a vehicle radar sensor to transmit and receive radio waves may include an antenna body in which one surface is stacked on the support surface; a through path formed inside the antenna body and extending in one direction; at least one slot formed through the through path toward the other surface of the antenna body and extending in the one direction; and a first radio wave absorbing member extending in the one direction and disposed parallel to opposite sides of the through path.

An antenna module is provided. According to an aspect of the present disclosure, an antenna module attached to a support surface provided in a vehicle radar sensor to transmit and receive radio waves may include an antenna body in which one surface is stacked on the support surface; a through path formed inside the antenna body and extending in one direction; at least one slot formed through the through path toward the other surface of the antenna body and extending in the one direction; and a first radio wave absorbing member extending in the one direction and disposed parallel to opposite sides of the through path.

A method for producing a layer of a device for electromagnetic radiation absorption, includes: providing a ply of powder material in the layer to be produced of the device; providing a predefined concentration distribution of particles for electromagnetic radiation absorption in the layer; providing a first binder and a second binder for the powder materials, wherein the first binder includes particles for the absorption of electromagnetic radiation, wherein the second binder includes a lower concentration of identical and/or different particles than the first binder; determining a mixing ratio between the first binder and the second binder for every position in the layer; selecting a position of the layer; mixing the first and second binder according to the mixing ratio for the selected position; wetting the powder material at the selected position using the mixed first and second binders; and repeating selecting, mixing, and wetting to produce the layer.

A method for producing a layer of a device for electromagnetic radiation absorption, includes: providing a ply of powder material in the layer to be produced of the device; providing a predefined concentration distribution of particles for electromagnetic radiation absorption in the layer; providing a first binder and a second binder for the powder materials, wherein the first binder includes particles for the absorption of electromagnetic radiation, wherein the second binder includes a lower concentration of identical and/or different particles than the first binder; determining a mixing ratio between the first binder and the second binder for every position in the layer; selecting a position of the layer; mixing the first and second binder according to the mixing ratio for the selected position; wetting the powder material at the selected position using the mixed first and second binders; and repeating selecting, mixing, and wetting to produce the layer.

A wellbore servicing tool. The wellbore servicing tool comprises a tool body, an electromagnetic transmitter coupled to the tool body, an electromagnetic receiver coupled to the tool body and spaced apart from the electromagnetic transmitter, wherein a portion of the tool body between the electromagnetic transmitter and the electromagnetic receiver defines a direct signal path between the electromagnetic transmitter and the electromagnetic receiver, and an absorbing material coupled to the tool body in the direct signal path between the electromagnetic transmitter and the electromagnetic receiver, proximate to the electromagnetic receiver.