US3720951A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave absorbing wall element
Assignee: TDK Corp
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Filing: 1970-11-30
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Granted: 1973-04-03
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Expires: 1990-11-30
Abstract
Abstract This invention provides a thin microwave absorbing wall member using a ferrite plate of which complex permeability is represented substantially by a formula:
Inventors
- 👤 Y Naito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:33
CPC Classifications
H; H01; H01Q; H01Q17/00; H01Q17/004
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
69 words
A microwave absorbing wall member constituted by a ferrite plate applied to a backing plate of electrically conductive metallic material, wherein the complex permeability of said ferrite plate is given substantially by a formula where Krelax : Mu i 1 where the direct current initial permeability Mu i is a value at the time of f 0 Tau : relaxation time Beta : a constant showing relaxation time distribution.
Claim 2
Dependent Claim
69 words
A microwave absorbing wall member constituted by a ferrite plate applied to a backing plate of electrically conductive metallic material, wherein the complex permeability of said ferrite plate is given substantially by a formula where Krelax : Mu i 1 where the direct current initial permeability Mu i is a value at the time of f 0 Tau : relaxation time Beta : a constant showing relaxation time distribution.
Claim 3
Dependent Claim
69 words
A microwave absorbing wall member constituted by a ferrite plate applied to a backing plate of electrically conductive metallic material, wherein the complex permeability of said ferrite plate is given substantially by a formula where Krelax : Mu i 1 where the direct current initial permeability Mu i is a value at the time of f 0 Tau : relaxation time Beta : a constant showing relaxation time distribution.
Claim 4
Dependent Claim
69 words
A microwave absorbing wall member constituted by a ferrite plate applied to a backing plate of electrically conductive metallic material, wherein the complex permeability of said ferrite plate is given substantially by a formula where Krelax : Mu i 1 where the direct current initial permeability Mu i is a value at the time of f 0 Tau : relaxation time Beta : a constant showing relaxation time distribution.
Claim 5
Dependent Claim
47 words
A microwave absorbing wall member as defined in claim 1 wherein said complex permeability of the ferrite plate is given substantially by a formula where fo : resonance frequency r : coefficient corresponding to loss Km : Mu i - 1 in the case when f 0.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |