Patent US4803494A successfully refreshed from Google Patents.
US4803494A
Expired / Lapsed
US
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Wide band antenna
Assignee: Nortel Networks Ltd
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Filing: 1988-01-20
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Granted: 1989-02-07
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Expires: 2008-01-20
Abstract
Abstract A cavity backed crossed slot antenna wherein the cavity depth d is less than one eighth of the operating wavelength λ at the lowest frequency of operation, the major dimension a of the cavity in the plane of the slots is less than one half of the wavelength λ at the lowest operating frequency, and the slots are excited by four symmetrically located capacitive coupled feed probes.
Inventors
- 👤 Andrew P. Norris
- 👤 Martin S. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:50
CPC Classifications
H; H01; H01Q; H01Q21/00; H01Q21/24; H01Q13/00; H01Q13/10; H01Q13/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
99 words
A cavity backed crossed slot antenna wherein the cavity depth is less than one eighth of the operating wavelength at the lowest frequency of operation, the major dimension of the cavity in the plane of the slots is less than one half of the wavelength at the lowest operating frequency, and the slots are excited by four capacitive coupled feed probes extending through the bottom wall of the cavity, the probes being located symmetrically with respect to the crossed slots and the ends of the probes being separated from the top wall by gaps to provide the capacitive coupling.
Claim 2
Dependent Claim
99 words
A cavity backed crossed slot antenna wherein the cavity depth is less than one eighth of the operating wavelength at the lowest frequency of operation, the major dimension of the cavity in the plane of the slots is less than one half of the wavelength at the lowest operating frequency, and the slots are excited by four capacitive coupled feed probes extending through the bottom wall of the cavity, the probes being located symmetrically with respect to the crossed slots and the ends of the probes being separated from the top wall by gaps to provide the capacitive coupling.
Claim 3
Dependent Claim
34 words
An antenna according to claim 1 wherein the top wall is provided with metal tuning screws each arranged to adjust the gaps between the top wall and the end of an associated feed probe.
Claim 4
Dependent Claim
13 words
An antenna according to claim 1 wherein the cavity contains solid dielectric material.
References Cited (Backward Citations)
US2557951A
Cited
GB653018A
Cited
US2832955A
Cited
US3031665A
Cited
US3009153A
Cited
JPS55128903A
Cited
US4242685A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-07 | 1992-08-08 | 1993-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-07 | 1996-08-08 | 1997-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-07 | 2000-08-08 | 2001-02-07 | $7700.00 | Window Closed / Lapsed |