US3754258A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear or planar retrodirective antenna system
Assignee: United States Department of the Navy
•
Filing: 1972-02-25
•
Granted: 1973-08-21
•
Expires: 1992-02-25
Abstract
Abstract A method and apparatus for obtaining automatic retrodirective performance from a linear or planar electromagnetic antenna array. The system may be employed in an active or passive manner and accomplishes selective retrodirectivity by the manipulation of the beam terminals on a multiple beam matrix. Also, control of the reradiated beam pattern is possible. Furthermore, this retrodirective system can also identify the angle of incidence of any particular transmission, and may therefore be employed as direction finding equipment.
Inventors
- 👤 H Coleman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:45
CPC Classifications
H; H01; H01Q; H01Q3/00; H01Q3/26; H01Q3/2605; H01Q3/2647; H01Q3/44; H01Q3/46
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
57 words
A passive retrodirective antenna system comprising: a plurality of linear or planar arrangement of antenna elements; multiple beam matrix means having a plurality of beam terminals; coupling means for coupling said antenna elements to said multiple beam matrix; individual open circuits of equal electrical length connected to said plurality of beam terminals such that retrodirective performance results.
Claim 2
Dependent Claim
57 words
A passive retrodirective antenna system comprising: a plurality of linear or planar arrangement of antenna elements; multiple beam matrix means having a plurality of beam terminals; coupling means for coupling said antenna elements to said multiple beam matrix; individual open circuits of equal electrical length connected to said plurality of beam terminals such that retrodirective performance results.
Claim 3
Dependent Claim
16 words
The system as claimed in claim 1 wherein said multiple beam matrix is a Butler matrix.
Claim 4
Dependent Claim
15 words
The system as claimed in claim 1 wherein said multiple beam matrix is a Blass-Lopez.
Claim 5
Dependent Claim
57 words
A passive retrodirective antenna system comprising: a plurality of linear or planar arrangement of antenna elements; multiple beam matrix means having a plurality of beam terminals; coupling means for coupling said antenna elements to said multiple beam matrix; individual short circuits of equal electrical length connected to said plurality of beam terminals such that retrodirective performance results.
Claim 6
Dependent Claim
57 words
A passive retrodirective antenna system comprising: a plurality of linear or planar arrangement of antenna elements; multiple beam matrix means having a plurality of beam terminals; coupling means for coupling said antenna elements to said multiple beam matrix; individual short circuits of equal electrical length connected to said plurality of beam terminals such that retrodirective performance results.
Claim 7
Dependent Claim
16 words
The system as claimed in claim 4 wherein said multiple beam matrix is a Butler matrix.
Claim 8
Dependent Claim
15 words
The system as claimed in claim 4 wherein said multiple beam matrix is a Blass-Lopez.
References Cited (Backward Citations)
US3255450A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |