US3680107A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wide band interference absorber and technique for electromagnetic radiation
Assignee: Individual
•
Filing: 1967-04-11
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Granted: 1972-07-25
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Expires: 1987-04-11
Abstract
Abstract A multiple-stage interference-type absorber for extinguishing a wide band of high-frequency electromagnetic waves by interference. The absorber includes a reflecting base layer on which are superposed at least two further layers having in combination a total thickness of about lambda /2 wherein lambda is the average wavelength in the frequency band to be extinguished. One of the superposed layers is adjacent the base layer and consists of an embedding material in which fillers are embedded to impart to the material an increased relative magnetic permeability. This layer has a thickness which is less than lambda /4. The other layer is of a loss-free material.
Inventors
- 👤 Hans H Meinke
- 👤 Kurt Ullrich
- 👤 Ludwig Wesch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:29
CPC Classifications
H; H01; H01Q; H01Q17/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
110 words
A multiple-stage interference-type absorber for extinguishing by interference a wide band of high-frequency electromagnetic waves impinging on said absorber, comprising a reflecting base layer and at least two further layers on said base layer, said further layers on the base layer having a total thickness of about lambda /2, lambda being the average wavelength in the material of the frequency band to be extinguished, the one of said further layers adjacent said base layer including an embedding mass and a filler in said mass imparting to the material an increased relative magnetic permeability, said one layer having a thickness under lambda /4, the other layer being of a loss-free material.
Claim 2
Dependent Claim
110 words
A multiple-stage interference-type absorber for extinguishing by interference a wide band of high-frequency electromagnetic waves impinging on said absorber, comprising a reflecting base layer and at least two further layers on said base layer, said further layers on the base layer having a total thickness of about lambda /2, lambda being the average wavelength in the material of the frequency band to be extinguished, the one of said further layers adjacent said base layer including an embedding mass and a filler in said mass imparting to the material an increased relative magnetic permeability, said one layer having a thickness under lambda /4, the other layer being of a loss-free material.
Claim 3
Dependent Claim
24 words
An absorber layer according to claim 1, wherein said embedding means is a material having a relative dielectric constant of between 1 and 6.
Claim 4
Dependent Claim
27 words
An absorber according to claim 2, wherein said reflecting base layer is of a metal having a wave impedance of about zero for waves in said band.
Claim 5
Dependent Claim
46 words
An absorber as claimed in claim 3, wherein said embedding mass is at least one of the materials selected from the group consisting of aniline formaldehyde, polyvinylalcohol, acetate, polyethylmethacrylate, neoprene, cellulose acetate, polyethylene, polyisobutylene, polychlorotrifluorethylene, polytetrafluorethylene, polyisobutyl methacrylate, polyvinylcyclohexane, natural rubber, natural bitumen and polyethyl methacrylate.
Claim 6
Dependent Claim
14 words
An absorber as claimed in claim 4, wherein the filler is a high-frequency iron.
Claim 7
Dependent Claim
14 words
An absorber as claimed in claim 4, wherein the filler is a ferromagnetic material.
Claim 8
Dependent Claim
34 words
An absorber as claimed in claim 4, wherein the filler is selected from the group consisting of aluminum, beryllium, zinc, copper, manganese, cadmium, chromium, molybdenum, in particle sizes of less than 100 Mu .
Claim 9
Dependent Claim
66 words
An absorber as claimed in claim 4, wherein the filler is selected from the group consisting of oxides of zinc, cadmium, magnesium, calcium, phosphides, antimonides and arsenides of indium, gallium; carbides, especially of calcium, silicon, titanium, aluminum, iron; silicides, carbonates; silicates; sulfates, phosphates; molybdates, tungstates; titanates; stannates; antimonates, arsenates, titanium dioxide, aluminum oxide, carbon black, graphite; and chalcogenides of the second group of the periodic table.
References Cited (Backward Citations)
US2992425A
Cited
US2822539A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |