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US4862174A
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Electromagnetic wave absorber
Assignee: Individual
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Filing: 1987-07-07
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Granted: 1989-08-29
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Expires: 2007-07-07
Abstract
Abstract An electromagnetic wave absorber containing a mixture of a magnetic material and a carbon material, both in powder form, in a binding medium so as to suspend both kinds of powder particles in space wherein the weight proportions of said binding medium taken as unity, said magnetic material in powder form, and said carbon material in powder form 1:F:C fall within the following limitation ranges: |F-C|≦0.3. 0.45≦F≦1.05. 0.45≦C≦1.05.
Inventors
- 👤 Yoshiyuki Naito
- 👤 Michiharu Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:51
CPC Classifications
H; H01; H01F; H01F1/00; H01Q; H01Q17/00; H01Q17/004
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
69 words
An electromagnetic wave absorber containing a mixture of a magnetic material and a carbon material, both in powder form, in a binding medium wherein the weight proportions of said binding medium taken as unity, said magnetic material in powder form, and said carbon material in powder form 1:F:C fall within the following limitation ranges: |F-C|≦0.3, 0.45≦F≦1.05, 0.45≦C≦1.05, where F represent the magnetic materials and C represents the carbon material.
Claim 2
Dependent Claim
69 words
An electromagnetic wave absorber containing a mixture of a magnetic material and a carbon material, both in powder form, in a binding medium wherein the weight proportions of said binding medium taken as unity, said magnetic material in powder form, and said carbon material in powder form 1:F:C fall within the following limitation ranges: |F-C|≦0.3, 0.45≦F≦1.05, 0.45≦C≦1.05, where F represent the magnetic materials and C represents the carbon material.
Claim 3
Dependent Claim
26 words
An electromagnetic wave absorber according to claim 1 wherein said magnetic material in powder form consists of a MnZn ferrite whose specific magnetic permeability is 2,700.
Claim 4
Dependent Claim
18 words
An electromagnetic wave absorber according to claim 1 wherein said carbon material in powder form consists of graphite.
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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) | 1992-08-28 | 1993-02-27 | 1993-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-28 | 1997-02-27 | 1997-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-28 | 2001-02-27 | 2001-08-29 | $7700.00 | Window Closed / Lapsed |