Abstract: The invention is a protective cover assembly having at least one part for a surface of a structure. In detail, the invention includes a first flexible layer of heat resistant material bonded to the structure having an outer surface with a radar cross-section reducing shape. A second layer of radar signature reducing material is bonded to outer surface of the first flexible layer and includes 1) a film of conductive material bonded to the first flexible layer; and 2) a film of radar absorbing material bonded to the film of conductive material. A third layer of heat resistant material is bonded to the second layer, the third layer made of a dielectric material having a thickness selected to provide a reduction in the radar cross-section of the cover when combined with the film of radar absorbing material.

Abstract: The invention relates to a device for exhausting hot gases with a reduced signature, for instance exhaust gases from an exhaust (7, 8) of a tank. The device is of the type comprising a means for mixing (9, 33) of the hot gases with fresh air from the exterior of the tank. To prevent the exhaust from, for instance, reflecting radar radiation and emit IR radiation, the device is provided with a protecting means (10, 34) which is positioned outside at least parts of said means. The device may comprise a space (12, 32) which accommodates preferably the entire means for mixing. The space is defined on the one hand by a shell (11, 31) towards the other spaces of the tank and, on the other hand, by the protecting means towards the exterior. The protecting means has openings (23, 25) for passing preferably a gas mixture from the means to the exterior and fresh air from the exterior to said means.

Abstract: The present invention provides a flame-retardant electromagnetic wave absorber that exhibits excellent formability and electromagnetic wave-absorbing properties, and can be easily assembled and constructed. The electromagnetic wave absorber comprises a wave-absorbing body and a base plate supporting the bottom thereof, wherein the wave-absorbing body is formed in a pyramid shape by fitting polygonal wave-absorbing plates into each other.

Abstract: The present invention is a multi-piece barrel shroud which provides IR signature and radar backscatter reduction over the entire length of the barrel by utilization of special radar absorbing materials and shaped in accordance with commonly known radar signature reduction techniques. The interior of the shroud includes cooling passages for the circulation of ambient air by way of a forced air circulation system which provides IR reduction. To facilitate barrel movement while minimizing weight, the majority of the shroud is stationary and is independent of the gun barrel. At least one other piece of the shroud is attached to the barrel near the muzzle end and designed to move in unison with the muzzle during recoil. The recoiling portion of the shroud is sized to mate with an annular recess within the distal end of the stationary portion so as to provide continuous shielding of the barrel throughout the entire range of recoil displacement.

Abstract: A rapidly deployable camouflage device for concealing recognizable signatures of military objects, comprising a camouflage balloon (1) and a deployment and undeployment device, the latter being equipped with a housing (2) and a fan (3) for inflating the balloon (1) arranged on an opening (4) in the housing. According to the invention, the balloon can be pulled into the housing by means of pull lines (7) secured at one end to the inside of the balloon opposite the opening (4), and at the other end to a motor-driven winding device inside the housing (2). The balloon is thus pulled in in such a way that it is reversed inside the housing, from which state if can then be blown out unreversed as rapidly deployable camouflage.

Abstract: The radar signature of a vessel is reduced by retrofitting it with an array (10) of elements (15) fastened to surfaces (14b) of the vessel. The elements (15) have planar faces (11-12) so oriented that incident radar signal (20) is reflected away from its angle of incidence.

Abstract: A method of minimizing reflectivity of an electromagnetic absorbing structure within a prescribed frequency range, including at least one skin layer having a thickness, at least one spacer layer having a thickness, and at least one resistivity sheet having a resistivity. Then, the thicknesses of the at least one skin layer, the at least one spacer layer, and the at least one resistivity sheet are determined.

Abstract: A device to conceal a radar or any other system for the transmission and reception of electromagnetic waves represents, for example, a pattern in relief. The device comprises at least one front part transparent to electromagnetic and optical waves, one rear part transparent to electromagnetic waves facing transmission and/or reception means and a form representing the manufacturer's logo placed between the parts. This form has an cellular structure with RF characteristics close to those of air. That device can be applied especially in radars equipping vehicles.

Abstract: According to the invention, there is provided a device enveloping said superstructure and able to reflect electromagnetic waves, said device comprising a truncated pyramidal frame (6) and a net (7) covering the small base of said frame (6).

Abstract: The present invention relates to a material of construction which includes a radar-dispersing metal foam, and to a vehicle to which a radar-dispersing metal foam has been applied. The radar-dispersing metal foam is capable of reducing the radar return from an object by a significant amount over a wide range of radar frequencies. The metal foam has a very low reflectivity to incident radar wave radiation.

Abstract: Disclosed is a device to conceal a radar fitted for example into a vehicle. This device bears especially a pattern. A method to make such a device is also disclosed. The device reproduces a given pattern comprising a shiny part. It comprises at least one front part transparent to optic waves and one part having a face with a shiny appearance before the rear face of the front part. The non-shiny part of the pattern covers the rear face of the front part. The invention can be applied especially to radars positioned on the front of vehicles. The cover then reproduces the manufacturer's logo.

Abstract: A non-skid, radar absorbing system 10. The system absorbs and scatters incident microwave and/or millimeter wave radiation so as to decrease retro reflectance. The system includes an absorbing layer (RAM) 14 juxtaposed with a substrate 12. Disposed adjacent the RAM 14 is a non-skid matrix layer 16 for providing a safe foot hold. Optionally, a protective environmental topcoat 18 is applied to the non-skid layer 16. The system has electrical and magnetic characteristics such that radar energy at a discrete or broadband frequencies is at least partially absorbed. The invention also includes methods of making and using the non-skid, radar absorbing system 10.

Abstract: An edge concealment system for abating electrical discontinuities between externally exposed edges of adjacent surface pieces separated by a gap. The system includes a cover component shrouding each edge and able to absorb or conduct incident radar energy. A male element and a female element extend between the cover component and the surface piece for positive engagement of the male element within the female element and retention of the cover component with the surface piece. Preferably the engagement of the male and female elements includes an audible signal such as a click sound when the engagement occurs so that operators are confirmatively advised upon positive placement.

Abstract: A glue-gun applied hot-melt radar-absorbing material (RAM) and method of use thereof is provided. The hot-melt radar-absorbing material composition comprises: (a) 70 to 85 wt % carbonyl iron powder; (b) 2 to 10 wt % of a metal deactivator; and (c) balance a thermoplastic polyurethane. The method for repair of a body comprising a radar-absorbing material, comprises: (a) formulating the hot-melt radar-absorbing material of the present invention; (b) forming the hot-melt radar-absorbing material into a shape; (c) applying the hot-melt radar-absorbing material in a molten state onto the body; and (d) allowing the hot-melt radar-absorbing material to cool to room temperature. The shape of the hot-melt RAM is advantageously a “glue stick”, which is configured to go into a glue gun. The repair operator loads the glue stick into the glue gun and pulls the trigger. The glue gun heats the glue stick, and the molten material is applied to the area to be repaired.

Abstract: Disclosed herein is a system for rapidly resolving position with centimeter-level accuracy for a mobile or stationary receiver [4]. This is achieved by estimating a set of parameters that are related to the integer cycle ambiguities which arise in tracking the carrier phase of satellite downlinks [5,6]. In the preferred embodiment, the technique involves a navigation receiver [4] simultaneously tracking transmissions [6] from Low Earth Orbit Satellites (LEOS) [2] together with transmissions [5] from GPS navigation satellites [1]. The rapid change in the line-of-sight vectors from the receiver [4] to the LEO signal sources [2], due to the orbital motion of the LEOS, enables the resolution with integrity of the integer cycle ambiguities of the GPS signals [5] as well as parameters related to the integer cycle ambiguity on the LEOS signals [6].

Abstract: A method for creating coherent masses of burning matter for countermeasures purposes such as for protecting an aircraft and other vehicles from infrared “heat seeking” hostile missiles and also from high power Laser beams and Laser radar. One or more spurious sources of radiation are created controllably in the general vicinity of the aircraft being protected; in missile countermeasures, each of these spurious sources is capable of emitting infrared energy comparable in wave length and at a higher intensity than that emitted by the target aircraft itself such that the hostile missile will be decoyed away from its intended target by the spurious radiation sources. In this method, the spurious source of radiation is created by igniting a small amount of aircraft fuel that is gelled and controllably ejected from the aircraft.

Abstract: A device to conceal a radar fitted into an automobile comprises at least one system of conductive wires perpendicular to the polarization of the wave sent out by the radar and reproducing a given graphic representation The graphic representation may be the automobile manufacturer's logo. The disclosed device can be applied especially to radars positioned in from of vehicles, for example of the ACC type.

Abstract: A gate such as a tollgate in an expressway for radar-mounted vehicles is disclosed, by which an erroneous operation of the mounted radar apparatus can be prevented and through which the radar-mounted vehicles can smoothly pass. The gate includes two partition walls which limit a passage. The positions of the front ends of the partition walls are separated in front and behind, or the front end of one or both of the partition walls has a structure for suppressing the frontward reflection of each radiated electric, optical, or acoustic beam incident on the relevant front end.

Abstract: An RF interface is configured as a laminate structure having a core layer of a ferromagnetic ceramic material, such as barium strontium titanate, whose permitivity is electrically controllable to modify the behavior of impinging electromagnetic energy, as one of minimally attenuated transmission, maximally attenuated absorption, and highly unattenuated reflection. Opposite surfaces of the ceramic core are coated with an electrically lossy material, such as indium tin oxide, to which a differential DC voltage is applied, and thereby imparting a DC electric field to the core layer. For an antenna application, during transmit/receive mode, the differential voltage has a magnitude that renders the laminate's core highly conductive, and thereby reflective to the RF wavelength being sourced from or received by an associated feed horn. During other times, the differential voltage renders the laminate effectively transparent to RF wavelengths in a prescribed band of interest (e.g.

Abstract: An electrically conductive member constituted by at least one member of the group consisting of carbon black, graphite and carbon fiber, a powdered or granulated material of an inorganic hollow body and inorganic reinforcing fiber are bonded to one another by an inorganic adhesive agent to thereby form an electric wave absorber. The electric wave absorber exhibits excellent electric wave absorbing power because of both the electrically conductive member and the powdered or granulated material of the inorganic hollow body which are contained in the electric wave absorber. The electric wave absorber has excellent mechanical strength because of the inorganic reinforcing fiber which is contained in the electric wave absorber. The electric wave absorber exhibits excellent nonflammable characteristic because of both the powdered or granulated material of the inorganic hollow body and the inorganic reinforcing fiber which are contained in the electric wave absorber.

Abstract: The invention relates to structural composite material able to absorb radar waves at frequencies of 18 GHz, 35 GHz and 94 GHz. This material comprises at least three layers of non-magnetic, dielectric material obtained by stacks of impregnated plies, including an outer layer with a low reflection index and losses having an effective dielectric permittivity of around 3, to promote the penetration of the incident radar waves, an intermediate layer having an effective dielectric permittivity of around 5, and an inner layer loaded with electrically conductive particles and having a substantial effective dielectric permittivity of around 15 to 20. The material may have applications in the manufacture of chests for military vehicles, for example.

Abstract: An electromagnetic wave absorber which is suitable for cellular phones, portable communication terminals and other portable electronic apparatus. The electromagnetic wave absorber is provided with a thin absorbing substrate formed of an electromagnetic wave absorbing material having a thickness of 0.01 .mu.m to 1.0 mm. Such a thin absorbing substrate is realized by making adjustment holes in the absorbing substrate and increasing a value of apparent magnetic permeability. Specifically, even in the absorbing substrate as thin as 0.8 mm, by making multiple adjustment holes, electromagnetic waves can be absorbed in a frequency ranging from 1.5 to 2.2 GHz.

Abstract: An aerosol generating device comprising a casing having a base end and a ainer end, with a firing primer mounted through the base end and extending into a propellant zone which contains a propellant. The firing primer is thereby detonationally connected to the propellant. A diffuser plate is mounted inside of the casing on a side of the propellant zone opposite to the firing primer. A filler area inside of the casing is adjacent to the diffuser on an opposite side to the propellant zone. The filler area contains particles of a powder having interstitial void space between the particles. A frangible end seal is attached to the casing within the retainer end, with the frangible end seal being positioned adjacent to the filler area on an opposite side of the diffuser. When activated, propellant gases expand through the diffuser into the fill area deagglomerating and fluidizing the powder particles and increasing pressure until the end seal ruptures and releases an aerosol cloud.

Abstract: Novel devices for providing shielding from and absorption of broadband electromagnetic radiation, and methods of manufacturing and using these devices, are disclosed. The device is comprised of a perforated electrical absorbing layer, containing conductive polymers, laminated to a metal plate. Additional layers may be incorporated into the device including one or more additional layers of electrical absorbing layers, magnetic absorbing layers and impedance matching layers.

Abstract: The disclosed jacket comprises a layer that is discreet with respect to the visible and infrared frequencies, having a specified thickness, with a specified dielectric permittivity and emissivity close to 1 for the infrared frequency bands considered; a resistive layer, with an electrical resistivity and thickness that are determined so that the inverse of their product gives a specified resistance; a layer of dielectric material with a specified thickness and a specified dielectric permittivity; and a conductive layer with electrical conductivity determined so that it is considered as a reflective plane for the radar frequencies considered.

Abstract: An armor plating for vehicles has at its outer side a layer (13) of plastics material bound explosive containing radar absorbing materials.

Abstract: An electromagnetic wave absorbing shielding material which is thin and lightweight and shows high electromagnetic wave absorbing capacity in a wide frequency region. The material comprises:(1) a one-dimensional conductive segment pattern which is a conductive segment pattern formed from a conductive material, wherein the conductive segment pattern has a length of more than 1/2 of the wavelength of the subjective electromagnetic wave, and the segment pattern has no electrical connection therebetween,(2) an electromagnetic wave shielding layer, and(3) an insulating intermediate material having a thickness of 0.1-10.0 mm, located between the one-dimensional conductive segment pattern (1) and the electromagnetic wave shielding layer (2).

Abstract: A device for the sensor signature reduction of cargo to be dropped from the air comprises a covering that essentially completely surrounds the cargo, which is made of a flexible material having a surface that reflects the expected radar radiation, wherein it is provided with openings for the inlet of ram air.

Abstract: Infrared, visible or mm. radiation is screened by an aerosol comprising flakes (0.03-0.3.times.1.5-20 microns) of aluminum metal composition, having a mass extinction coefficient of at least 4.5 m.sup.2 /g in respect of infrared radiation and at least 3.5 m.sup.2 /g in respect of visible radiation. The invention includes also the flakes per se, and formulations containing them, the flakes being additionally characterized by the facts that the amount of manufacturing process additive with which they are coated has been reduced to between 0 and 2.5 weight percent, and that they have a bulk density at least 0.5, preferably at least 1.5 g/cc. The reduction in the coating additive may be achieved by modifying the amount of additive used in the manufacturing process, or by treating the conventionally manufactured flakes with solvents to reduce the amount of coating additive to the desired level.

Abstract: An electronic attenuation and camouflage device comprising a novel cooling device comprised of microspheres; an additional set of microspheres containing radar attenuating materials <RAM> capable of absorbing certain frequencies; and an additional set of microspheres containing electro-reactive substances enabling color change of a structure to match background, all comprising structures or being placed in a matrix; a structure; a machined part; a coating; or a series of matrices, structures, parts or coatings, which combined structures enable concealment of an object.

Abstract: A reactive armor box for protecting armor surfaces comprising a base for achment to the armor surfaces, a plurality of walls extending from the base at an angle to provide an enclosed space, a plurality of explosive cassettes disposed within the enclosed space and supported and contained within the walls, and a top, attached to the walls to contain the cassettes in the enclosed space, which has radar absorbing characteristics for absorbing radio waves of the radar to avoid detection of the protected armor surface and to protect the armor surface from projectiles utilizing radio frequency guidance seekers. The top and the entire structure of the box on the invention may be formed of a light weight composite material which has the radar absorbing characteristics or the box may be formed of conventional metals with only the top surface of the box being formed of the radar absorbing materials.

Abstract: A ultrablack article made of a resin containing light absorbing pigments or dyes and its method of manufacture. The surface of the article is provided with light reflecting projections that cause incident light to reflect from the sides of such projections at least twice and preferably at least three times before reflecting from the articles surface. The vast majority of the incident light is thereby transmitted into the article where it is absorbed. The projections are advantageously conical, pyramidal or ridge shaped. The total incident light that reflects from the surface and from the interior of the article is not greater than 0.5%.The surface can be made by applying cone or pyramid shaped light beams to photoresist stepwise to make cones and pyramids and by scanning to make ridges. Means are provided to transfer such surfaces to more suitable resins and to do so continuously.

Abstract: An inflatable shield for suppressing the characteristic radiation signature of a satellite is described. The shield is conical-shaped and made from a thin synthetic polymer film material coated with a radiation reflecting material, such as gold or aluminum. At least one subliming agent is contained within the shield to inflate the shield when exposed to heat. An ultraviolet curable slurry coats the inner walls of the shield and permanently hardens the shield upon exposure to ultraviolet radiation from a self-contained source. The shield optionally may include absorbing and desiccant agents to absorb unwanted gas and water and prevent interference with the primary mission of the satellite. Additional means may be included for moving and positioning the shield with respect to the satellite.

Abstract: Ferrites as an electromagnetic wave absorber have their unique attenuation ranges depending on their compositions. The possibility of controlling attenuation characteristics of ferrite absorber by forming laminates of ferrite is disclosed. This invention provides that the center frequency of laminated ferrites could be changed arbitrarily employing ferrite with different composition and thickness. The method consists of stacking at least two soft ferrite layers (Ni-Zn, Mn-Zn) with various thickness.

Abstract: A layered microwave radiation absorber comprises an absorbing layer bound to one side of a conductive layer (such as a metallic plate or foil), and an adhesive layer bound on the other side of the conductive layer. The combination may be applied directly to the surface of any object, but especially to an existing conductive object coated with an nonconductive coating (such as paint) without removing the nonconductive coating from the surface. Several types of absorbing materials may be used, and other layers may be included. The absorber has superior resistance to delamination.

Abstract: A vehicle in free space or air, with external surfaces primarily fashioned from planar facets. The planar facets or panels are angularly positioned to reduce scattered energy in the direction of the receiver. In particular, radar signals which strike the vehicle are primarily reflected at an angle away from the search radar or are returned to the receiver with large variations of amplitude over small vehicle attitude changes.

Abstract: A radar absorbing material comprising multiple layers integrated to form a thin, flexible, and lightweight structure. The material includes a substrate having disposed thereon absorber elements that are resistively loaded to enable one to construct a device relatively small and thin size. The broadbanding of the device is carried out by multilayering concepts in which different size antenna patterns are multilayered with each layer designed to absorb frequencies in a specified range. The absorber elements are selected for their intrinsic impedance properties and preferrably be polarization insensitive. These absorber elements are disposed in a random and preferrably aperiodic pattern.

Abstract: A millimeter wave screening cloud is formed comprised of an aerosol of fine ibers of a carbon composition, in which the particles are of micron diameter and millimeter length. The cloud is formed by aerosolizing a compact mass of carbon composition fibers through the action of explosively bursting such compact mass in the atmosphere at the desired cloud location.

Abstract: Dielectric or magnetic anisotropy layers, laminated composite material incorporating said layers and their production process. The laminated material has at least two stacks of assembled layers, a first stack constituted by a layer (2) of first dielectric fibers (4) oriented parallel to a first direction (x), and a layer (6) of first magnetic fibers (8) oriented parallel to a second direction (y) perpendicular to the first direction (x), and a second stack constituted by a layer (10) of second dielectric fibers (12) oriented parallel to the second direction (y), and a layer (14) of second magnetic fibers oriented parallel to the first direction (x). Each fiber is constituted by a thermoplastic polymer sheath containing a pulverulent magnetic or dielectric charge.

Abstract: The present disclosure describes a protective tarpaulin which protects military targets from detection and destruction by multiple weapon systems. The tarpaulin comprises a thermal protective sheet situated at its bottom surface in contact with the target it covers. A multi-cell honeycomb structure is disposed above and separated from the thermal protective sheet by a plurality of stiffeners. The tarpaulin also includes a temperature control means, in communication with an air gap defined by the space between the multi-cell honeycomb structure and the thermal protective sheet.

Abstract: For reduction in occupation space without sacrifice of the responsible broad bandwidth, an electromagnetic wave absorber for electromagnetic waves is provided with an absorbing sheet formed of a non-woven fabric containing conductive fibers mixed with insulative fibers, and each of the conductive fibers is selected from the group consisting of a metal fiber or a resin fiber coated with a conductive material.

Abstract: A canopy screening an object, especially its thermally emitted waves and/or against hf electromagnetic waves in the microwave range, especially radar waves, has external textile sheets (1, 2) connected by a support fabric (13), i.e., a spacer, which forms a center space (10). At least one external surface, i.e. its filaments are provided with a coating (6, 7) which in part or in whole is reflecting in the thermal range and/or absorbing in the microwave range.

Abstract: A radar attenuator shield for a space vehicle is described having an open shell of radar attenuating material presenting a smooth external surface on one side and open on the opposite side in the general shape of a bathtub. The space vehicle is ensconced within the open side for minimizing radar echo. In a preferred embodiment the external surface of the radar attenuator shield is in the form of a semi-cylinder with one-fourth of a sphere at each end thereof.

Abstract: The invention is a reduced radar detectable runway. In detail, the invention comprises a runway having a plurality of holes randomly orientated and randomly dispersed across and along the surface thereof. The holes are preferably polygons, and ideally square in shape, and filled with a dielectric material. Additionally, the minimum necessary perimeter of the runway should include an extended portion in an irregular pattern about a least a portion of the necessary perimeter. This portion should also incorporate the randomly positioned and orientated holes.

Abstract: The present invention relates to fiber structures and methods for obtaining tuned response to high frequency electromagnetic radiation, particularly at microwave frequencies. In one embodiment, a woven fabric is prepared with ferrite filled fibers oriented perpendicular to dielectric filled fibers. The fill of the fibers is selected to reflect radiation having a known frequency and polarization. In other embodiments, tuned structures are provided by disposing sheets containing oriented ferrite and dielectric fibers parallel to one another and moving the layers relative to one another to achieve the desired impedance for incident radiation.

Abstract: High magnetic permeability composites are obtained by incorporating ferrite fibers in the composites. The ferrite fibers consist of a polymer and particulate ferrite fill at a concentration above the percolation threshold for the ferrite fill in the polymer (typically greater than 30 volume percent). The aspect ratio and ferrite concentration of the fibers are selected to minimize demagnetization fields in the fibers. The fibers can be dispersed in low concentration in an unoriented fashion in the composites to impart high magnetic permeability to the composite. In other embodiments, the fibers are oriented in the composites to impart high magnetic permeability to the composite for incident radiation of a particular linear polarization.

Abstract: A radar return suppressor for use in concealing and camouflaging mobile targets such as trucks, artillery and like vehicles. One or more lengths of a support member attachable to the target and components support and position a radar signal attenuator between the target and the anticipated radar source. In one embodiment, the attenuator is a multiplicity of closely spaced flexible plastic strands having radar signal absorbing material dispersed in the strands to form a labyrinth to entrap and absorb the radar signal. In a second embodiment the labyrinth of strands is replaced by an intertwined plastic vine-like structure secured in the support member for absorbing the energy of the radar signal.

Abstract: The present invention is a method for making radar chaff consisting of metal rings having varying diameters, using photolithographic processes. One aspect of the invention has the steps of: providing a metal foil having a thickness suitable for use in radar chaff; overcoating the metal foil with a photoresist, to form a layered structure; undercoating the metal foil with a removable backing; exposing the photoresist to a quantity of actinic radiation for chemically modifying the photoresist into a photoproduct suitable for subsequent development, where the actinic radiation is patterned into a series of concentric rings; developing the photoresist, to expose the underlying metal in a series of concentric rings; removing the exposed metal to form a series of concentric metal rings on the removable backing; and removing the removable backing. Another aspect of the invention is a metal chaff precursor, comprising: a removable backing, coated with a plurality of concentric metal foil rings.

Abstract: A vehicle in free space or air, with external surfaces primarily fashioned from planar facets. The planar facets or panels are angularly positioned to reduce scattered energy in the direction of the receiver. In particular, radar signals which strike the vehicle are primarily reflected at an angle away from the search radar or are returned to the receiver with large variations of amplitude over small vehicle attitude changes.