US4369447A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Annular slot antenna
Assignee: EMI Ltd
•
Filing: 1980-07-10
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Granted: 1983-01-18
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Expires: 2000-07-10
Abstract
Abstract The antenna comprises an open-mouthed cylindrical cavity 1 defined by side 11 and bottom 12 walls. A conductive coating 5 on an insulative substrate 4 lies on the bottom wall 12. The coating 5 is spaced from the side wall 11 by an annular space 2. A coaxial line 7, 8 feeds microwave energy to the zone between the coating 5 and the wall 12. That zone acts as a radial transmission line which couples the coaxial line to the cavity.
Inventors
- 👤 Kenneth J. Edney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:22
CPC Classifications
H; H01; H01Q; H01Q1/00; H01Q1/36; H01Q1/38; H01Q13/00; H01Q13/10; H01Q13/18
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
114 words
An antenna comprising an open mouthed cylindrical cavity defined by an electrically conducting side wall of uniform diameter, and by an electrically conducting bottom wall, an electrically insulating support member lying on the bottom wall, an electrically conducting plate mounted to the support member in a position spaced from and facing the mouth of the cavity to define a space between the plate and bottom wall, and being electrically isolated from the wall to define a substantially annular slot between the plate and side wall, and means for feeding electromagnetic energy of microwave frequency to, or receiving such energy from, said space to thereby feed the energy to or receive energy from the cavity.
Claim 2
Dependent Claim
114 words
An antenna comprising an open mouthed cylindrical cavity defined by an electrically conducting side wall of uniform diameter, and by an electrically conducting bottom wall, an electrically insulating support member lying on the bottom wall, an electrically conducting plate mounted to the support member in a position spaced from and facing the mouth of the cavity to define a space between the plate and bottom wall, and being electrically isolated from the wall to define a substantially annular slot between the plate and side wall, and means for feeding electromagnetic energy of microwave frequency to, or receiving such energy from, said space to thereby feed the energy to or receive energy from the cavity.
Claim 3
Dependent Claim
23 words
An antenna according to claim 1 wherein the electrically conducting plate comprises an electrically conducting coating applied to said electrically insulating support member.
Claim 4
Dependent Claim
15 words
An antenna according to claim 1 or 2, wherein the cavity is circular in cross-section.
Claim 5
Dependent Claim
15 words
An antenna according to claim 1 or 2, wherein the cavity is semi-circular in cross-section.
Claim 6
Dependent Claim
35 words
An antenna according to claim 1 or 2, wherein the feeding means comprises a coaxial line portion having a central conductor connected to the said plate and an outer conductor connected to the bottom wall.
Claim 7
Dependent Claim
19 words
An antenna according to claim 1 or 2 further comprising a ground plane surrounding the mouth of the cavity.
References Cited (Backward Citations)
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GB847035A
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US3239838A
Cited
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Cited
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Cited
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Cited
US3774223A
Cited
US4229744A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-01-17 | 1986-07-19 | 1987-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-17 | 1990-07-19 | 1991-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-17 | 1994-07-19 | 1995-01-18 | $7700.00 | Window Closed / Lapsed |