US4359737A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Artificial trees for absorbing and scattering radiation
Assignee: United States Department of the Army
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Filing: 1981-01-26
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Granted: 1982-11-16
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Expires: 2001-01-26
Abstract
Abstract Countermeasures apparatus is disclosed for attenuating radiation by absoron, reflection, and/or scattering, whether the radiation is reflected by or emanates from a target to be protected. The countermeasures apparatus comprises an artificial tree having a plurality of leaves disposed between the target to be protected and radiation sensors whereby the radiation directed from the target to the sensors is attentuated, the radiation being of a plurality of different wavelengths. Attenuating means are disposed on the leaves and take the form of an array of electrically conductive particles forming dipoles whose lengths are chosen to be 0.48 or approximately one-half of the wavelengths of the wavelength of the radiation to be defeated. The dipoles of the array are spaced from each other a spacing within an optimum range of one-half to one of the wavelength of the radiation of interest to effect coherent absorption and scattering of this radiation.
Inventors
- 👤 John W. Bond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:58
CPC Classifications
H; H01; H01Q; H01Q17/00; H01Q17/008; A; A41; A41G; A41G1/00; A41G1/001; A41G1/007
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
87 words
Countermeasures apparatus for attenuating the flow of multi-spectral radiation of at least first and second wavelengths from a target to detectors thereof, said countermeasures apparatus comprising: (a) an artificial tree adapted to be readily mounted upon the target and including a plurality of leaves disposed between the target and the sensors, said artificial tree made of a dielectric material; and (b) means disposed on said leaves for attenuating said radiation of each of said first and second wavelengths, thereby preventing detection of the target by the sensors.
Claim 2
Dependent Claim
87 words
Countermeasures apparatus for attenuating the flow of multi-spectral radiation of at least first and second wavelengths from a target to detectors thereof, said countermeasures apparatus comprising: (a) an artificial tree adapted to be readily mounted upon the target and including a plurality of leaves disposed between the target and the sensors, said artificial tree made of a dielectric material; and (b) means disposed on said leaves for attenuating said radiation of each of said first and second wavelengths, thereby preventing detection of the target by the sensors.
Claim 3
Dependent Claim
89 words
The countermeasures apparatus as claimed in claim 1, wherein said artificial tree has a bottom end adapted to be mounted to the target and a top end, said radiation attenuating means comprising first means for attenuating radiation of the first wavelength and second means for attenuating radiation of the second wavelength longer than the first wavelength, said first means disposed upon said leaves closer to said top end of said artificial tree and said second means disposed on said leaves closer to said bottom end of said artificial tree.
Claim 4
Dependent Claim
41 words
The countermeasures apparatus as claimed in claim 1, wherein said radiation attenuating means comprises first and second pluralities of dipoles made of an electrically conductive material and having lengths selected to be approximately one-half of said first and second wavelengths, respectively.
Claim 5
Dependent Claim
66 words
The countermeasures apparatus as claimed in claim 3, wherein said artificial tree includes a bottom end adapted to be mounted on the target and a top end, said wavelength being longer than said first wavelength, said first plurality of dipoles being disposed on said leaves closer to said top end and said second plurality of wavelengths being disposed on said leaves closer to said bottom end.
Claim 6
Dependent Claim
39 words
The countermeasures apparatus as claimed in claim 1, wherein said radiation attenuation means comprises dipoles, said dipoles being disposed upon said leaves and spaced an effective distance from each other to effect coherent absorption and scattering of the radiation.
Claim 7
Dependent Claim
68 words
The countermeasures apparatus as claimed in claim 5, wherein there are first and second plurality of dipoles, said first plurality of dipoles are spaced from each other an effective distance within an optimum range of one-half to one of said first wavelength, and said second plurality of dipoles are spaced from each other an effective distance within an optimum range of one-half to one of said second wavelength.
Claim 8
Dependent Claim
45 words
The countermeasures apparatus as claimed in claim 6, wherein each of said first plurality of dipoles has a length equal to approximately one-half the first wavelength, and each of said second plurality of dipoles has a length equal to approximately one-half of the second wavelength.
Claim 9
Dependent Claim
28 words
The countermeasures apparatus as claimed in claim 1, wherein said artificial tree comprises a trunk and a plurality of branches adapted to be removably mounted from said trunk.
Claim 10
Dependent Claim
51 words
The countermeasures apparatus as claimed in claim 8, wherein said trunk comprises a bottom portion adapted to be mounted upon the target and an upper portion having a plurality of holes therein, each of said plurality of holes receiving a branch, each of said branches supporting a plurality of said leaves.
Claim 11
Dependent Claim
39 words
The countermeasures apparatus as claimed in claim 9, wherein each of said branches includes means for orienting said branch and its leaves with respect to the target whereby said radiation attenuating means is effectively disposed to attenuate the radiation.
Claim 12
Dependent Claim
45 words
The countermeasures apparatus as claimed in claim 9, wherein said bottom portion is of a sufficient length to form a space between the target and the lowermost branches and their leaves, whereby air is permitted to circulate in said space to effectively remove thermal radiation.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-15 | 1986-05-17 | 1986-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-15 | 1990-05-17 | 1990-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-15 | 1994-05-17 | 1994-11-16 | $7700.00 | Window Closed / Lapsed |