Patent JPS5598671A successfully refreshed from Google Patents.
US5223849A
Expired / Lapsed
US
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Broadband electromagnetic energy absorber
Assignee: Parker Intangibles LLC
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Filing: 1988-04-11
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Granted: 1993-06-29
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Expires: 2008-04-11
Abstract
Abstract A radar absorbing material comprising multiple layers integrated to form a thin flexible and light weight structure. The material includes a substrate disposed thereon antenna elements that are relatively loaded to enable one to construct a device in relatively small and thin size. The broad handling of the device is carried out by multi-layering concepts in which different size antenna patterns are multi-layered with each layer designed to absorb frequencies in s specified range. The antenna elements are selected for their intrinsic broadband properties and to preferably be polarization insensitive.
Inventors
- 👤 Raymond S. Kasevich
- 👤 John F. Broderick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:08
CPC Classifications
H; H01; H01Q; H01Q17/00; H01Q15/00; H01Q15/0006; H01Q15/0013; H01Q15/0026
Claims Analysis
Total Claims: 94
Claim 1
Independent Claim
110 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements each comprise a spiral element.
Claim 2
Dependent Claim
110 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements each comprise a spiral element.
Claim 3
Dependent Claim
111 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements each comprise a circularly polarized element.
Claim 4
Dependent Claim
111 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements each comprise a circularly polarized element.
Claim 5
Dependent Claim
17 words
Radar absorbing apparatus as set forth in claim 2 wherein said elements each comprises a dielectric layer.
Claim 6
Dependent Claim
15 words
Radar absorbing apparatus as set forth in claim 3 wherein said dielectric layer comprises plastic.
Claim 7
Dependent Claim
15 words
Radar absorbing apparatus as set forth in claim 3 wherein said dielectric layer comprises rubber.
Claim 8
Dependent Claim
33 words
Radar absorbing apparatus as set forth in claim 2 wherein said means for resistively loading includes means for forming the elements themselves of a partially conductive resistive layer deposited on said supporting means.
Claim 9
Dependent Claim
22 words
Radar absorbing apparatus as set forth in claim 6 wherein said resistive layer has an impedance in the range of 0.04-1.50 ohms/square.
Claim 10
Dependent Claim
27 words
Radar absorbing apparatus as set forth in claim 2 wherein said means for resistively loading includes means for forming a resistor at a terminal of the element.
Claim 11
Dependent Claim
23 words
Radar absorbing apparatus as set forth in claim 2 including means for loading the means for supporting the elements to make it lossy.
Claim 12
Dependent Claim
19 words
Radar absorbing apparatus as set forth in claim 2 wherein said dielectric layer comprises a high temperature resistant layer.
Claim 13
Dependent Claim
17 words
Radar absorbing apparatus as set forth in claim 2 wherein said dielectric layer comprises a ceramic material.
Claim 14
Dependent Claim
17 words
Radar absorbing apparatus as set forth in claim 2 wherein said dielectric layer comprises a ceramic composite.
Claim 15
Dependent Claim
17 words
Radar absorbing apparatus as set forth in claim 2 wherein said elements each comprise separate spiral patterns.
Claim 16
Dependent Claim
110 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements each comprise a bi-conical element.
Claim 17
Dependent Claim
110 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements each comprise a bi-conical element.
Claim 18
Dependent Claim
111 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements each comprise a logarithmically periodic element.
Claim 19
Dependent Claim
111 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements each comprise a logarithmically periodic element.
Claim 20
Dependent Claim
135 words
Radar absorging apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, means for loading the means for supporting the elements to make it lossy, wherein said means for loading includes materials selected from the group of glass spheres, carbon particles, rutile, graphite, and ferrite.
Claim 21
Dependent Claim
135 words
Radar absorging apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, means for loading the means for supporting the elements to make it lossy, wherein said means for loading includes materials selected from the group of glass spheres, carbon particles, rutile, graphite, and ferrite.
Claim 22
Dependent Claim
122 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, and coating means of a lossy material selected from a group including graphite and ferrite-graphite mixtures in an epoxy base.
Claim 23
Dependent Claim
122 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, and coating means of a lossy material selected from a group including graphite and ferrite-graphite mixtures in an epoxy base.
Claim 24
Dependent Claim
133 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, and a second antenna array also comprised of a plurality of discrete absorber elements, and means for supporting said second array spaced from said first array remote from said reflector means.
Claim 25
Dependent Claim
133 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, and a second antenna array also comprised of a plurality of discrete absorber elements, and means for supporting said second array spaced from said first array remote from said reflector means.
Claim 26
Dependent Claim
29 words
Radar absorbing apparatus as set forth in claim 18 wherein said second array is for absorbing electromagnetic energy in a different frequency band than that of the first array.
Claim 27
Dependent Claim
25 words
Radar absorbing apparatus as set forth in claim 19 wherein the elements of the first array are smaller than the elements of the second array.
Claim 28
Dependent Claim
32 words
Radar absorbing apparatus as set forth in claim 20 wherein the first array and second array both comprise dipoles with the first array dipoles shorter in length than the second array dipoles.
Claim 29
Dependent Claim
110 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements each comprise a trapezoid configuration.
Claim 30
Dependent Claim
110 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements each comprise a trapezoid configuration.
Claim 31
Dependent Claim
19 words
Radar absorbing apparatus as set forth in claim 22 wherein the elements are disposed in an offset trapezoidal configuration.
Claim 32
Dependent Claim
109 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequecny signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements are of spiral configuration.
Claim 33
Dependent Claim
109 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequecny signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements are of spiral configuration.
Claim 34
Dependent Claim
110 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequecny signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements each comprise a zig-zag configuration.
Claim 35
Dependent Claim
110 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequecny signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein said elements each comprise a zig-zag configuration.
Claim 36
Dependent Claim
19 words
Radar absorbing apparatus as set forth in claim 25 wherein the elements are disposed in an offset zig-sag configuration.
Claim 37
Dependent Claim
112 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequecny signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein the elements comprised first and second different size elements.
Claim 38
Dependent Claim
112 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequecny signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the absorber elements therethrough to change the impedance thereof to in turn alter the gain thereof thereby decreasing signal re-radiation, said array disposed at a distance from said reflector means, wherein the elements comprised first and second different size elements.
Claim 39
Dependent Claim
23 words
Radar absorbing apparatus as set forth in claim 27 wherein the elements of first size are interspersed with the elements of second size.
Claim 40
Dependent Claim
21 words
Radar absorbing apparatus as set forth in claim 28 wherein the first and second size elements are both of spiral configuration.
Claim 41
Dependent Claim
23 words
Radar absorbing apparatus as set forth in claim 28 wherein the first size elements are trapezoidal and the second size elements are spiral.
Claim 42
Dependent Claim
23 words
Radar absorbing apparatus as set forth in claim 28 wherein the first size elements are zig-zag and the second size elements are spiral.
Claim 43
Dependent Claim
128 words
Broadband radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a first array comprised of a plurality of discrete absorber elements, means for supporting said first array from and in front of said electrically conductive reflector means and in at least a first planar configuration, said first array adapted for absorption over a first predetermined frequency segment included in said frequency range, a second array also comprised of a plurality of discrete absorber elements, and means for supporting said second array spaced from said first array remote from said reflector means, said second array adapted for absorbing electromagnetic energy in a second frequency segment included in said frequency range.
Claim 44
Dependent Claim
128 words
Broadband radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a first array comprised of a plurality of discrete absorber elements, means for supporting said first array from and in front of said electrically conductive reflector means and in at least a first planar configuration, said first array adapted for absorption over a first predetermined frequency segment included in said frequency range, a second array also comprised of a plurality of discrete absorber elements, and means for supporting said second array spaced from said first array remote from said reflector means, said second array adapted for absorbing electromagnetic energy in a second frequency segment included in said frequency range.
Claim 45
Dependent Claim
18 words
Broadband radar absorbing apparatus as described in claim 32 including means for resistively loading each of the arrays.
Claim 46
Dependent Claim
30 words
Broadband radar absorbing apparatus as described in claim 33 wherein said means for resistively loading include means for forming the elements by a resistive ink deposited on said dielectric layer.
Claim 47
Dependent Claim
38 words
Broadband radar absorbing apparatus as described in claim 33 wherein each array is disposed at a distance from said reflector means on the order of one-tenth wavelength or less of the electromagnetic energy wave associated with each wave.
Claim 48
Dependent Claim
23 words
Broadband radar absorbing apparatus as described in claim 35 wherein the means for supporting the elements comprises a dielectric layer for each array.
Claim 49
Dependent Claim
27 words
Broadband radar absorbing apparatus as described in claim 36 wherein said means for resistively loading include means for forming a resistor at a terminal of the element.
Claim 50
Dependent Claim
15 words
Broadband radar absorbing apparatus as described in claim 32 wherein the elements comprises dipole elements.
Claim 51
Dependent Claim
15 words
Broadband radar absorbing apparatus as described in claim 32 wherein the elements comprises spiral elements.
Claim 52
Dependent Claim
16 words
Broadband radar absorbing apparatus as described in claim 32 wherein the elements comprises circularly polarized elements.
Claim 53
Dependent Claim
15 words
Broadband radar absorbing apparatus as described in claim 32 wherein the elements comprise bi-conical elements.
Claim 54
Dependent Claim
17 words
Broadband radar absorbing apparatus as described in claim 32 wherein the elements comprise logarithmically periodic antenna elements.
Claim 55
Dependent Claim
19 words
Broadband radar absorbing apparatus as described in claim 32 wherein the elements comprise first and second different size elements.
Claim 56
Dependent Claim
23 words
Broadband radar absorbing apparatus as described in claim 43 wherein the elements of first size are interspersed with the elements of second size.
Claim 57
Dependent Claim
17 words
Broadband radar absorbing apparatus as described in claim 32 wherein the elements each comprise a trapezoid configuration.
Claim 58
Dependent Claim
17 words
Broadband radar absorbing apparatus as described in claim 32 wherein the elements each comprise a zig-zag configuration.
Claim 59
Dependent Claim
98 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber element, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the elements therethrough, said resistive loading being in a range on the order of 0.04-2.0 ohms/square, wherein said elements comprises first and second different size elements.
Claim 60
Dependent Claim
98 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber element, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the elements therethrough, said resistive loading being in a range on the order of 0.04-2.0 ohms/square, wherein said elements comprises first and second different size elements.
Claim 61
Dependent Claim
118 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber element, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the elements therethrough, said resistive loading being in a range on the order of 0.04-2.0 ohms/square, including a second array also comprised of a plurality of discrete absorber elements, and means for supporting said second array spaced from said first array remote from said reflector means.
Claim 62
Dependent Claim
118 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete broadband impedance absorber element, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for substantially uniformly resistively loading the elements therethrough, said resistive loading being in a range on the order of 0.04-2.0 ohms/square, including a second array also comprised of a plurality of discrete absorber elements, and means for supporting said second array spaced from said first array remote from said reflector means.
Claim 63
Dependent Claim
29 words
Radar absorbing apparatus as set forth in claim 48 wherein said second array is for absorbing electromagnetic energy in a different frequency band than that of the first array.
Claim 64
Dependent Claim
21 words
Radar absorbing apparatus as set forth in claim 48 wherein each element comprises a spiral element having an open central area.
Claim 65
Dependent Claim
18 words
Radar absorbing apparatus as set forth in claim 50 including a ferrite disk in the open center area.
Claim 66
Dependent Claim
99 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an array comprised of a plurality of discrete absorber elements, means for supporting said array from and in front of said electrically conductive reflector means and in a planar configuration, said elements including elements of first and second different size, said first size elements adapted for absorption primarily over a first frequency segment included in said frequency range, said second size elements adapted for absorption primarily over a second frequency segment included in said frequency range.
Claim 67
Dependent Claim
99 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an array comprised of a plurality of discrete absorber elements, means for supporting said array from and in front of said electrically conductive reflector means and in a planar configuration, said elements including elements of first and second different size, said first size elements adapted for absorption primarily over a first frequency segment included in said frequency range, said second size elements adapted for absorption primarily over a second frequency segment included in said frequency range.
Claim 68
Dependent Claim
15 words
Radar absorbing apparatus as set forth in claim 52 wherein said elements are polarization insensitive.
Claim 69
Dependent Claim
17 words
Radar absorbing apparatus as set forth in claim 52 wherein said elements are both of like shape.
Claim 70
Dependent Claim
23 words
Radar absorbing apparatus as set forth in claim 52 wherein said first size elements are trapezoidal and the second size elements are spiral.
Claim 71
Dependent Claim
23 words
Radar absorbing apparatus as set forth in claim 52 wherein the first size elements are zig-zag and the second size elements are spiral.
Claim 72
Dependent Claim
21 words
Radar absorbing apparatus as set forth in claim 52 wherein the first and second size elements are both of spiral configuration.
Claim 73
Dependent Claim
98 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having a frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, an array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for resistively loading the absorber elements, said array disposed at a distance from said reflector means, wherein said elements each comprise separate spiral patterns, wherein the separate patterns have different turn spacings.
Claim 74
Dependent Claim
98 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having a frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, an array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for resistively loading the absorber elements, said array disposed at a distance from said reflector means, wherein said elements each comprise separate spiral patterns, wherein the separate patterns have different turn spacings.
Claim 75
Dependent Claim
15 words
Radar absorbing apparatus as set forth in claim 58 wherein said spiral patterns are concentric.
Claim 76
Dependent Claim
21 words
Radar absorbing apparatus as set forth in claim 59 wherein said outer patterns have greater turn spacing than the inner patterns.
Claim 77
Dependent Claim
18 words
Radar absorbing apparatus as set forth in claim 60 wherein the spiral patterns are isolated from each other.
Claim 78
Dependent Claim
16 words
Radar absorbing apparatus as set forth in claim 60 wherein said separate patterns are contiguously connected.
Claim 79
Dependent Claim
118 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, an array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for resistively loading the absorber elements, said array disposed at a distance from said reflector means, wherein said means for supporting the elements is comprised of different segments of different dielectric constant with the different segments being associated respectively with the element and outside the element so to enable tuning of the array.
Claim 80
Dependent Claim
118 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, an array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for resistively loading the absorber elements, said array disposed at a distance from said reflector means, wherein said means for supporting the elements is comprised of different segments of different dielectric constant with the different segments being associated respectively with the element and outside the element so to enable tuning of the array.
Claim 81
Dependent Claim
107 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency singal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, an array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for resistively loading the absorber elements, said array disposed at a distance from said reflector means, wherein each element comprises a spiral element having a main spiral having plural open loops, in combination with plurality of smaller spirals disposed in the loops.
Claim 82
Dependent Claim
107 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency singal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, an array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for resistively loading the absorber elements, said array disposed at a distance from said reflector means, wherein each element comprises a spiral element having a main spiral having plural open loops, in combination with plurality of smaller spirals disposed in the loops.
Claim 83
Dependent Claim
24 words
Radar absorbing apparatus as set forth in claim 64 wherein said main spiral includes a pair of contiguous spiral segments of different turns spacing.
Claim 84
Dependent Claim
127 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, an array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for resistively loading the absorber elements, said array disposed at a distance from said reflector means, wherein said elements comprise first and second sets of spiral patterns, a first set being of spiral form and second set disposed in the interstitial spaces defined by the first set and being of modified spiral and complimentary form to the patterns of the first set.
Claim 85
Dependent Claim
127 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, an array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for resistively loading the absorber elements, said array disposed at a distance from said reflector means, wherein said elements comprise first and second sets of spiral patterns, a first set being of spiral form and second set disposed in the interstitial spaces defined by the first set and being of modified spiral and complimentary form to the patterns of the first set.
Claim 86
Dependent Claim
111 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, an array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for resistively loading the absorber elements, said array disposed at a distance from said reflector means, a second antenna array also comprised of a plurality of discrete absorber elements, and means for supporting said second array spaced from said first array remote from said reflector means.
Claim 87
Dependent Claim
111 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, an array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for resistively loading the absorber elements, said array disposed at a distance from said reflector means, a second antenna array also comprised of a plurality of discrete absorber elements, and means for supporting said second array spaced from said first array remote from said reflector means.
Claim 88
Dependent Claim
81 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, an array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for resistively loading the absorber elements, wherein the elements comprised first and second different size elements.
Claim 89
Dependent Claim
81 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, an array comprised of a plurality of discrete broadband impedance absorber elements, means for supporting said absorber elements from and in front of said electrically conductive reflector means and in at least a first planar array, means for resistively loading the absorber elements, wherein the elements comprised first and second different size elements.
Claim 90
Dependent Claim
91 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave incident thereupon having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete and relatively spacially disposed broadband impedance absorber elements, means for supporting said absorber elements, said array disposed at a distance measured in the direction of propagation of said electromagnetic energy wave from said reflector means, said array characterized by having a resistivity in a range on the order of 0.04-2.0 ohms/square.
Claim 91
Dependent Claim
91 words
Radar absorbing apparatus for absorbing an electromagnetic energy wave incident thereupon having frequency signal content in a frequency range including 2-18 GHz, said apparatus comprising; an electrically conductive reflector means, a substantially planar array comprised of a plurality of discrete and relatively spacially disposed broadband impedance absorber elements, means for supporting said absorber elements, said array disposed at a distance measured in the direction of propagation of said electromagnetic energy wave from said reflector means, said array characterized by having a resistivity in a range on the order of 0.04-2.0 ohms/square.
Claim 92
Dependent Claim
19 words
Radar absorbing apparatus as set forth in claim 69 wherein each broadband impedance absorber element comprises a spiral element.
Claim 93
Dependent Claim
31 words
Radar absorbing apparatus as set forth in claim 69 wherein said resistivity is obtained by resistively loading the impedance absorber elements by forming substantially the entire element by a resistive film.
Claim 94
Dependent Claim
37 words
Radar absorbing apparatus as set forth in claim 69 wherein said electrically conductive reflector means is disposed in a first plane and said planar array is disposed in a second plane substantially parallel to said first plane.
References Cited (Backward Citations)
US3185986A
Cited
US4439768A
Cited
US4684952A
Cited
US4525720A
Cited
US4539433A
Cited
US4675690A
Cited
US4605934A
Cited
US4742354A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-06-28 | 1996-12-28 | 1997-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-28 | 2000-12-28 | 2001-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-28 | 2004-12-28 | 2005-06-29 | $7700.00 | Window Closed / Lapsed |