NO306918B1 - Material structure for absorption of electromagnetic waves - Google Patents
Material structure for absorption of electromagnetic waves Download PDFInfo
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- NO306918B1 NO306918B1 NO894440A NO894440A NO306918B1 NO 306918 B1 NO306918 B1 NO 306918B1 NO 894440 A NO894440 A NO 894440A NO 894440 A NO894440 A NO 894440A NO 306918 B1 NO306918 B1 NO 306918B1
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- 239000000463 material Substances 0.000 title claims description 38
- 238000010521 absorption reaction Methods 0.000 title claims description 11
- 229920000642 polymer Polymers 0.000 claims description 34
- -1 polyethylene Polymers 0.000 claims description 31
- 239000004698 Polyethylene Substances 0.000 claims description 22
- 229920000573 polyethylene Polymers 0.000 claims description 22
- 239000002245 particle Substances 0.000 claims description 8
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims description 4
- 239000004793 Polystyrene Substances 0.000 claims description 4
- 239000002131 composite material Substances 0.000 claims description 4
- 229920002223 polystyrene Polymers 0.000 claims description 4
- 229920002943 EPDM rubber Polymers 0.000 claims description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 3
- 229920000265 Polyparaphenylene Polymers 0.000 claims description 3
- 239000004677 Nylon Substances 0.000 claims description 2
- 239000004952 Polyamide Substances 0.000 claims description 2
- 239000004721 Polyphenylene oxide Substances 0.000 claims description 2
- 239000004743 Polypropylene Substances 0.000 claims description 2
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 claims description 2
- XECAHXYUAAWDEL-UHFFFAOYSA-N acrylonitrile butadiene styrene Chemical compound C=CC=C.C=CC#N.C=CC1=CC=CC=C1 XECAHXYUAAWDEL-UHFFFAOYSA-N 0.000 claims description 2
- 229920001940 conductive polymer Polymers 0.000 claims description 2
- 230000000694 effects Effects 0.000 claims description 2
- 150000002576 ketones Chemical class 0.000 claims description 2
- 239000000178 monomer Substances 0.000 claims description 2
- 229920001778 nylon Polymers 0.000 claims description 2
- 229920002239 polyacrylonitrile Polymers 0.000 claims description 2
- 229920002647 polyamide Polymers 0.000 claims description 2
- 229920001707 polybutylene terephthalate Polymers 0.000 claims description 2
- 229920000515 polycarbonate Polymers 0.000 claims description 2
- 239000004417 polycarbonate Substances 0.000 claims description 2
- 229920000570 polyether Polymers 0.000 claims description 2
- 229920000139 polyethylene terephthalate Polymers 0.000 claims description 2
- 239000005020 polyethylene terephthalate Substances 0.000 claims description 2
- 229920001155 polypropylene Polymers 0.000 claims description 2
- 229920002635 polyurethane Polymers 0.000 claims description 2
- 239000004814 polyurethane Substances 0.000 claims description 2
- 239000004800 polyvinyl chloride Substances 0.000 claims description 2
- 229920000915 polyvinyl chloride Polymers 0.000 claims description 2
- 229920005653 propylene-ethylene copolymer Polymers 0.000 claims description 2
- 239000004065 semiconductor Substances 0.000 claims description 2
- 230000003313 weakening effect Effects 0.000 claims description 2
- 239000010410 layer Substances 0.000 description 19
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- 230000002745 absorbent Effects 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 238000000862 absorption spectrum Methods 0.000 description 1
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 229920001197 polyacetylene Polymers 0.000 description 1
- 229920000123 polythiophene Polymers 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
- B32B27/302—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
- B32B27/304—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/02—Elements
- C08K3/08—Metals
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/04—Homopolymers or copolymers of ethene
- C08L23/06—Polyethene
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q17/00—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/20—Properties of the layers or laminate having particular electrical or magnetic properties, e.g. piezoelectric
- B32B2307/212—Electromagnetic interference shielding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2323/00—Polyalkenes
- B32B2323/04—Polyethylene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2325/00—Polymers of vinyl-aromatic compounds, e.g. polystyrene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2327/00—Polyvinylhalogenides
- B32B2327/06—PVC, i.e. polyvinylchloride
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/16—Elastomeric ethene-propene or ethene-propene-diene copolymers, e.g. EPR and EPDM rubbers
Description
Foreliggende oppfinnelse gjelder en materialstruktur for absorpsjon av elektromagnetiske bølger, særlig i det radarbølgebånd som ligger mellom 8 og 12 GHz. The present invention relates to a material structure for the absorption of electromagnetic waves, particularly in the radar waveband that lies between 8 and 12 GHz.
Det er kjent at visse polymerer kan anvendes som absorbatorer for elektromagnetiske bølger, slik dette for eksempel er omtalt av A. Feldblum (1981 - J. Pol. Sei. 19, 173). It is known that certain polymers can be used as absorbers for electromagnetic waves, as discussed for example by A. Feldblum (1981 - J. Pol. Sei. 19, 173).
Absorpsjonsegenskapene er således blitt studert for polyacetylen, polyparafenylen og polytiofen med hensyn til bølger innenfor frekvensområdet mellom 100 Mhz og 10 GHz. Vanligvis skjematiseres det foreliggende problem på følgende måte. Det gjelder å komme frem til et material som er stabilt i den omgivende luftatmosfære og innenfor et temperaturområde på mellom -100°C og +100°C, og hvis effektive ledningsevne a i henhold til litteraturen bør ligge omkring 10"<2>(ohmcm)"<1>, mens dets følsomhet for temperaturvariasjoner må være lav og dets relative permittivitet e i forhold til luft må ligge så nær som mulig verdien 1, for å oppnå størst mulig absorpsjon av en innfallende bølge samt for å gjøre dens refleksjon ved opptaksflaten tilnærmet lik null. The absorption properties have thus been studied for polyacetylene, polyparaphenylene and polythiophene with respect to waves within the frequency range between 100 Mhz and 10 GHz. Usually, the present problem is schematized in the following way. It is necessary to arrive at a material which is stable in the surrounding air atmosphere and within a temperature range of between -100°C and +100°C, and whose effective conductivity a according to the literature should be around 10"<2> (ohmcm) "<1>, while its sensitivity to temperature variations must be low and its relative permittivity e in relation to air must be as close as possible to the value 1, in order to achieve the greatest possible absorption of an incident wave and to make its reflection at the recording surface approximately equal zero.
De ovenfor nevnte polymerer, særlig når de er dopet med tilsatsmaterial for å oppfylle fordringene til ledningsevne, er ikke i stand til å spesielt oppfylle disse fordringer, og spesielt da ikke, på den ene side, fordringene til stabilitet overfor luft og temperaturvariasjoner, og på den annen side absorpsjonsegenskaper, særlig når de er kombinert med det formål å danne sammensatte enkeltsjikt av polymerer med dielektriske egenskaper. The above-mentioned polymers, especially when they are doped with additive material to meet the requirements for conductivity, are not able to meet these requirements in particular, and especially not, on the one hand, the requirements for stability against air and temperature variations, and on on the other hand, absorption properties, especially when they are combined for the purpose of forming composite single layers of polymers with dielectric properties.
Videre foreligger det allerede metallkombinerte polymerer, særlig sådanne tilsatt jern, på det kommersielle område, hvor de selges av Emerson and Cumming Company. Disse har den ulempe at de har høy densitet og kan frembringe et stort magnetisk moment, med den følge at det opptrer en topp i absorpsjonsspekteret. Furthermore, there are already metal-combined polymers, especially those with added iron, in the commercial area, where they are sold by the Emerson and Cumming Company. These have the disadvantage that they have a high density and can produce a large magnetic moment, with the consequence that a peak appears in the absorption spectrum.
Det er da et formål for foreliggende oppfinnelse å frembringe en absorberende materialstruktur som gjør det mulig å overvinne disse ulemper og som har særlig gode egenskaper i frekvensområder mellom 8 og 12 GHz, med en jevn absorpsjonskoeffisient innenfor det tilsiktede frekvensområde. It is then an object of the present invention to produce an absorbent material structure which makes it possible to overcome these disadvantages and which has particularly good properties in frequency ranges between 8 and 12 GHz, with a uniform absorption coefficient within the intended frequency range.
Foreliggende oppfinnelse gjelder således en materialstruktur for absorpsjon av elektromagnetiske bølger, særlig i frekvensbåndet 8-12 GHz, og som omfatter strukturlag med henholdsvis svekkende og isolerende virkning på sådanne bølger som faller inn på materialstrukturen, idet strukturen på denne bakgrunn av kjent teknikk har som særtrekk den omfatter en stabel An av tynne lag oppnådd fra et A-lag i et material valgt fra en materialgruppe av halvlederpolymerer og fyllstofftilsatte polymerer, og fra et B-lag i et material valgt fra en materialgruppe av isolerende polymerer, polyetylen, polystyren og polyvinylklorid, idet stabelen er bygget opp på følgende måte: The present invention thus relates to a material structure for the absorption of electromagnetic waves, particularly in the frequency band 8-12 GHz, and which comprises structural layers with respective weakening and insulating effects on such waves that fall onto the material structure, the structure having this background of known technology as a distinctive feature it comprises a stack An of thin layers obtained from an A layer in a material selected from a material group of semiconductor polymers and filler-added polymers, and from a B layer in a material selected from a material group of insulating polymers, polyethylene, polystyrene and polyvinyl chloride, as the stack is built up in the following way:
An = f(An-1. Bn-l) med Bn<=>9(An-1. Bn-l). An = f(An-1. Bn-l) with Bn<=>9(An-1. Bn-l).
slik at stabelen får en lagsekvens bestemt av funsksjonene f og g. so that the stack gets a layer sequence determined by the functions f and g.
Som eksempler kan det angis at følgende lagstabler An da kan frembringes: As examples, it can be stated that the following layer stacks An can then be produced:
Funksjonene f og g er således konstante over hele utstrekningen av gjentagelses-sekvensen, slik at lagstabelen blir uregelmessig organisert. The functions f and g are thus constant over the entire extent of the repetition sequence, so that the layer stack is irregularly organized.
Det endelige formål for en sådan materialstruktur er særlig å komme frem til et inkom-mensurabelt forhold mellom den bølge som skal påvirkes og strukturens geometriske egenskaper. Det kan vises at dette må føre til en oppsamling av energien inne i selve materialstrukturen, og derfor til total absorpsjon. The ultimate purpose of such a material structure is in particular to arrive at an incommensurable relationship between the wave to be affected and the geometric properties of the structure. It can be shown that this must lead to a collection of the energy within the material structure itself, and therefore to total absorption.
I henhold til en foretrukket utførelse har materialet i lag A (eller B) en sammensatt oppbygning som omfatter: - en polymer basert på polyetylen og isolerende polymer, hvor vektandelen av polyetylen er mellom 55 og 75 %, - en tilsats av nikkelpulver hvis partikkelstørrelse ligger mellom 1 og 20 p og hvis fylningsgrad regnet i volumandel ligger mellom 5 og 35 %, According to a preferred embodiment, the material in layer A (or B) has a composite structure comprising: - a polymer based on polyethylene and insulating polymer, where the weight proportion of polyethylene is between 55 and 75%, - an addition of nickel powder whose particle size lies between 1 and 20 p and whose degree of filling calculated in volume proportion is between 5 and 35%,
mens B-laget (eller A-laget) utgjøres av nevnte polymer basert på polyetylen og isolerende polymer. while the B layer (or A layer) consists of said polymer based on polyethylene and insulating polymer.
Følgende parameterverdier utgjør foretrukne utførelser: The following parameter values constitute preferred embodiments:
- en partikkelstørrelse på mellom 3 og 20 pm, og særlig omkring 5 pm, - a particle size of between 3 and 20 pm, and in particular around 5 pm,
- en fylningsgrad på mellom 15 og 25 %, og helst på omtrent 19 %, og - a degree of filling of between 15 and 25%, and preferably of approximately 19%, and
- en andel av polyetylen i vedkommende polymer på omkring 65 %. - a proportion of polyethylene in the relevant polymer of around 65%.
I henhold til en annen utførelse har materialet i lag A (eller B) en sammensatt oppbygning som omfatter: According to another embodiment, the material in layer A (or B) has a complex structure that includes:
- en isolerende polymer som inneholder polyetylen i en vektandel på mellom 55 og - an insulating polymer containing polyethylene in a proportion by weight of between 55 and
75 %, - en tilsats av ledende polymerer hvis partikkelstørrelse ligger mellom 0,5 og 100 pm og med vektandel i den isolerende polymer på mellom 5 og 90 %, 75%, - an addition of conductive polymers whose particle size is between 0.5 and 100 pm and with a weight proportion in the insulating polymer of between 5 and 90%,
idet et ytterligere B-lag (eller A-lag) utgjøres i sin helhet av nevnte isolerende polymer. in that a further B layer (or A layer) is made up entirely of said insulating polymer.
Denne isolerende polymer omfatter fortrinnsvis en polymer valgt fra en polymergruppe bestående av EPDM, styren-butadien-akrylonitril, propylenetylen-kopolymermonomer, høytrykkspolyetylen, lavtrykkspolyetylen, rettlinjekjedet lavtrykkspolyetylen, polyamid (nylon), polyakrylonitril, polybutylen-tereftalat, polykarbonat, polyetylen, ketoneter-polyeter, polyetylenoksyd, polyetylen-tereftalat, polypropylen, polyetylenoksyd, polyfenylensulfid, polystyren og polyuretan. This insulating polymer preferably comprises a polymer selected from a polymer group consisting of EPDM, styrene-butadiene-acrylonitrile, propylene-ethylene copolymer monomer, high-pressure polyethylene, low-pressure polyethylene, straight-chain low-pressure polyethylene, polyamide (nylon), polyacrylonitrile, polybutylene terephthalate, polycarbonate, polyethylene, ketone ether-polyether , polyethylene oxide, polyethylene terephthalate, polypropylene, polyethylene oxide, polyphenylene sulphide, polystyrene and polyurethane.
Ytterligere særtrekk og fordeler ved foreliggende oppfinnelse vil fremgå av den etter-følgende beskrivelse av anskueliggjørende, men ikke-begrensende utførelseseksempler gitt med henvisning til den vedføyde tegning, på hvilken: Fig. 1 viser variasjon i refleksjonsfaktoren R for forskjellige materialstrukturer i henhold Further distinctive features and advantages of the present invention will be apparent from the subsequent description of illustrative, but non-limiting examples given with reference to the attached drawing, in which: Fig. 1 shows variation in the reflection factor R for different material structures according to
til oppfinnelsen, som funksjon av frekvensen i GHz, to the invention, as a function of the frequency in GHz,
fig. 2 er av samme art som fig. 1 for frekvensområdet mellom 8 og 12 GHz, og fig. 3 er av samme art som fig. 2, men for andre materialstrukturer i henhold til fig. 2 is of the same type as fig. 1 for the frequency range between 8 and 12 GHz, and fig. 3 is of the same type as fig. 2, but for other material structures according to
oppfinnelsen. the invention.
Utgangspunktet for oppfinnelsen er et material som tillater fremstilling av et lag A, hvis sammensatte materialstruktur omfatter: - en polymer basert på polyetylen og EPDM, hvor andelen (i vekt) av polyetylen er The starting point for the invention is a material that allows the production of a layer A, whose composite material structure includes: - a polymer based on polyethylene and EPDM, where the proportion (by weight) of polyethylene is
65 %, og 65%, and
- en nikkelpulvertilsats med partikkelstørrelse på omkring 5 pm, og med en fylningsgrad regnet i volum på i størrelsesorden 24 %. - a nickel powder additive with a particle size of around 5 pm, and with a degree of filling calculated by volume of around 24%.
Ved også å fremstille et lag B, som bare består av den ovenfor nevnte polymer, kan det så opprettes en stabel av første orden: A1= ABA, dvs. en stabel som omfatter to A-lag med et mellomliggende B-lag. Denne stabel blir påført en metallflate. By also producing a layer B, which only consists of the above-mentioned polymer, a stack of the first order can then be created: A1= ABA, i.e. a stack comprising two A layers with an intermediate B layer. This stack is applied to a metal surface.
Tabellen nedenfor angir elektriske og mekaniske egenskaper for disse lag, idet e er den relative permittivitet i forhold til luft, p er den relative permeabilitet og p er resistiviteten. The table below indicates electrical and mechanical properties for these layers, where e is the relative permittivity in relation to air, p is the relative permeability and p is the resistivity.
Videre fremstilles ytterligere stabler: Furthermore, additional stacks are produced:
- av 2. orden: A2= A1B1A1 med B1= BBB - of 2nd order: A2= A1B1A1 with B1= BBB
- av 3. orden: A3<=>A2<B>2A2med B2<=>B1B1<B>1- of 3rd order: A3<=>A2<B>2A2with B2<=>B1B1<B>1
- av 4. orden: A4<=>A3B3<A>3med B3<=><B>2<B>2B2, og - of the 4th order: A4<=>A3B3<A>3with B3<=><B>2<B>2B2, and
- av 5. orden: A5<=>A4<B>4A4med B4<=><B>3B3B3- of the 5th order: A5<=>A4<B>4A4with B4<=><B>3B3B3
Den totale tykkelse av disse stabler er alltid lik 2250 pm. The total thickness of these stacks is always equal to 2250 pm.
Fig. 1 viser variasjonen i refleksjonsfaktoren R for disse forskjellige stabler A.,, A2, A3, A4, A5, som funksjon av frekvensen angitt i GHz. Fig. 2 angir de samme kurver som i fig. 1, men i forstørret målestokk og bare innenfor området 8-12 GHz. Av denne figur fremgår det at stabelen A3av 3. orden er særlig fordelaktig innenfor dette frekvensområde. Denne stabel med en tykkelse på 2,25 mm tillater en bølgeabsorpsjon på mellom 90 og 99 %, hvilket er meget bedre enn absorp-sjonen for stabelen A1av 1. orden. Valget av gjentageisessekvens er således ytterst viktig. Fig. 1 shows the variation in the reflection factor R for these different stacks A.,, A2, A3, A4, A5, as a function of the frequency indicated in GHz. Fig. 2 indicates the same curves as in fig. 1, but on an enlarged scale and only within the range 8-12 GHz. From this figure it appears that the stack A3 of the 3rd order is particularly advantageous within this frequency range. This stack with a thickness of 2.25 mm allows a wave absorption of between 90 and 99%, which is much better than the absorption of the stack A1 of the 1st order. The choice of repetition sequence is thus extremely important.
De samme type stabler som tidligere fremstilles, men denne gang med A'.,, A'2, A'3, A'4, A'5av en slik utførelse at stabelens totale tykkelse blir lik 1800 pm. The same type of stacks as previously manufactured, but this time with A'.,, A'2, A'3, A'4, A'5 of such a design that the stack's total thickness is equal to 1800 pm.
Fig. 3 som er av samme art som fig. 2, viser da fordelen ved stabelen A'3av 3. orden i nevnte område mellom 8 og 12 GHz. Fig. 3 which is of the same type as fig. 2, then shows the advantage of the stack A'3 of the 3rd order in the aforementioned range between 8 and 12 GHz.
Oppfinnelsen er naturligvis ikke begrenset til de beskrevne utførelser, og særlig ikke når det gjelder de anvendte materialer og sjikttykkelsene i stablene. The invention is of course not limited to the described embodiments, and especially not when it comes to the materials used and the layer thicknesses in the stacks.
Claims (14)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8814940A FR2737347B1 (en) | 1988-11-17 | 1988-11-17 | STRUCTURE FOR THE ABSORPTION OF ELECTROMAGNETIC WAVES |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| NO894440L NO894440L (en) | 1996-08-13 |
| NO306918B1 true NO306918B1 (en) | 2000-01-10 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NO894440A NO306918B1 (en) | 1988-11-17 | 1989-11-08 | Material structure for absorption of electromagnetic waves |
Country Status (8)
| Country | Link |
|---|---|
| BE (1) | BE1010512A4 (en) |
| CA (1) | CA2003074C (en) |
| DE (1) | DE3936195C2 (en) |
| FR (1) | FR2737347B1 (en) |
| GB (1) | GB2310541B (en) |
| IT (1) | IT1267133B1 (en) |
| NL (1) | NL8902827A (en) |
| NO (1) | NO306918B1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2249862C1 (en) * | 2004-07-02 | 2005-04-10 | Общество с ограниченной ответственностью "НПО"АЙРЭС Технолоджис" | Device for structuring electromagnetic field |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2996709A (en) * | 1945-04-27 | 1961-08-15 | Du Pont | Flexible electromagnetic radiationabsorptive article |
| US3349397A (en) * | 1966-02-03 | 1967-10-24 | North American Aviation Inc | Flexible radiation attenuator |
| US3721982A (en) * | 1970-11-10 | 1973-03-20 | Gruenzweig & Hartmann | Absorber for electromagnetic radiation |
| SE8007075L (en) * | 1979-10-31 | 1981-05-01 | Illinois Tool Works | SKERMNING |
| US4353069A (en) * | 1980-09-10 | 1982-10-05 | Handel Peter H | Absorptive coating for the reduction of the reflective cross section of metallic surfaces and control capabilities therefor |
| DE3307066A1 (en) * | 1983-03-01 | 1984-09-13 | Dornier Gmbh, 7990 Friedrichshafen | MULTILAYER FIBER COMPOSITE |
| US4680236A (en) * | 1986-02-18 | 1987-07-14 | The Bf Goodrich Company | Electrodeless heterogeneous polypyrrole composite |
| GB2192756A (en) * | 1986-07-07 | 1988-01-20 | Hoybond Limited | Energy absorbing coatings and their use in camouflage |
-
1988
- 1988-11-17 FR FR8814940A patent/FR2737347B1/en not_active Expired - Fee Related
-
1989
- 1989-10-31 DE DE3936195A patent/DE3936195C2/en not_active Expired - Fee Related
- 1989-11-03 GB GB8924797A patent/GB2310541B/en not_active Expired - Fee Related
- 1989-11-07 IT IT06795589A patent/IT1267133B1/en active IP Right Grant
- 1989-11-08 NO NO894440A patent/NO306918B1/en not_active IP Right Cessation
- 1989-11-15 NL NL8902827A patent/NL8902827A/en active Search and Examination
- 1989-11-16 CA CA002003074A patent/CA2003074C/en not_active Expired - Fee Related
- 1989-11-16 BE BE8901211A patent/BE1010512A4/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| IT8967955A0 (en) | 1989-11-07 |
| CA2003074A1 (en) | 1996-10-11 |
| IT8967955A1 (en) | 1991-05-07 |
| NO894440L (en) | 1996-08-13 |
| DE3936195A1 (en) | 1997-03-06 |
| GB2310541A (en) | 1997-08-27 |
| DE3936195C2 (en) | 1999-02-18 |
| NL8902827A (en) | 1997-08-01 |
| FR2737347A1 (en) | 1997-01-31 |
| CA2003074C (en) | 2001-01-09 |
| BE1010512A4 (en) | 1998-10-06 |
| GB8924797D0 (en) | 1996-12-18 |
| IT1267133B1 (en) | 1997-01-24 |
| GB2310541B (en) | 1998-01-07 |
| FR2737347B1 (en) | 1997-12-19 |
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