US3594804A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrically controlled reflective surface employing ferrite material
Assignee: EMI Ltd
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Filing: 1968-08-21
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Granted: 1971-07-20
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Expires: 1988-08-21
Abstract
Abstract In a microwave system a microwave reflector is provided which is capable of selective displacement. The reflector is formed by a layer of ferrite material, and a nonferromagnetic microwave reflecting surface behind said layer. The selective displacement is produced by means for selectively inducing a magnetic field within said ferrite layer, the arrangement being such that changes in the magnetic condition of said ferrite layer cause said layer to change from a transparent state to a reflecting state for microwave energy.
Inventors
- 👤 Wolfgang Hersch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:28
CPC Classifications
H; H01; H01Q; H01Q3/00; H01Q3/26; H01Q3/2664; H01Q19/00; H01Q19/10; H01Q19/18; H01Q19/19
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
97 words
In a microwave system, a microwave reflecting surface which is capable of selective displacement, including a nonferromagnetic microwave reflecting surface and a ferrite ring on said surface, said ring comprising a plurality of sectors, means for inducing a magnetic field in a selected one of said sectors so as to change the magnetic condition of the ferrite in the selected sector from a substantially transparent to a substantially reflecting condition for microwave energy and vice versa, wherein the distance between the front surface of said ring and said reflecting surface is electromagnetically equivalent to the required displacement.
Claim 2
Dependent Claim
97 words
In a microwave system, a microwave reflecting surface which is capable of selective displacement, including a nonferromagnetic microwave reflecting surface and a ferrite ring on said surface, said ring comprising a plurality of sectors, means for inducing a magnetic field in a selected one of said sectors so as to change the magnetic condition of the ferrite in the selected sector from a substantially transparent to a substantially reflecting condition for microwave energy and vice versa, wherein the distance between the front surface of said ring and said reflecting surface is electromagnetically equivalent to the required displacement.
Claim 3
Dependent Claim
112 words
In a microwave system, a microwave reflecting surface which is capable of selective displacement, including a layer of ferrite material, a nonferromagnetic reflecting surface situated behind said layer of ferrite material, and commutating means for selectively changing the magnetic condition of different parts of said layer in a prearranged order to produce a scanning system, the arrangement being such that a change in the magnetic condition of a part of said layer causes said part to change from a substantially transparent to a substantially reflecting condition for microwave energy and vice versa, the distance between the front surface of said layer and said reflecting surface being electromagnetically equivalent to the required displacement.
Claim 4
Dependent Claim
112 words
In a microwave system, a microwave reflecting surface which is capable of selective displacement, including a layer of ferrite material, a nonferromagnetic reflecting surface situated behind said layer of ferrite material, and commutating means for selectively changing the magnetic condition of different parts of said layer in a prearranged order to produce a scanning system, the arrangement being such that a change in the magnetic condition of a part of said layer causes said part to change from a substantially transparent to a substantially reflecting condition for microwave energy and vice versa, the distance between the front surface of said layer and said reflecting surface being electromagnetically equivalent to the required displacement.
Claim 5
Dependent Claim
118 words
A microwave antenna system including a reflector comprising a layer of ferrite backed by a nonferromagnetic microwave reflecting surface, respective control means for producing a magnetic field in respective parts of said layer, and means for selectively energizing said control means, whereby microwave energy, incident on a part of said layer, is reflected either from the front surface of said layer or from said reflecting surface in dependence upon the presence or absence in said part of a magnetic field produced by said control means, the thickness of the layer being such that said incident microwave energy is reflected to different spatial positions, separated by a required distance, in dependence upon the surface from which it is reflected.
Claim 6
Dependent Claim
118 words
A microwave antenna system including a reflector comprising a layer of ferrite backed by a nonferromagnetic microwave reflecting surface, respective control means for producing a magnetic field in respective parts of said layer, and means for selectively energizing said control means, whereby microwave energy, incident on a part of said layer, is reflected either from the front surface of said layer or from said reflecting surface in dependence upon the presence or absence in said part of a magnetic field produced by said control means, the thickness of the layer being such that said incident microwave energy is reflected to different spatial positions, separated by a required distance, in dependence upon the surface from which it is reflected.
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) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |