US3731313A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Van-atta array antenna device
Assignee: Toshiba Corp
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Filing: 1971-09-09
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Granted: 1973-05-01
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Expires: 1991-09-09
Abstract
Abstract In a Van-Atta array antenna device of the type wherein a plurality of equally spaced antenna elements are disposed in parallel and respective pairs of antenna elements disposed symmetrically with respect to the center of the antenna array are interconnected by feeders of substantially the same length, impedance matching stubs having an adjustable length are connected to substantially the center of respective feeders in order to enable incoming electromagnetic waves to be reradiated either straight backward or in an opposite direction to that in which they are receiving, with respect to the antenna boresight, without changing the characteristic impedance of feeders.
Inventors
- 👤 K Nagai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:52
CPC Classifications
H; H01; H01Q; H01Q3/00; H01Q3/44; H01Q3/46
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
123 words
A Van-Atta array antenna device comprising: a plurality of antenna elements juxtaposed at substantially equal distances from each other; every two of said elements being disposed in a symmetrical relationship with respect to the center of said aNtenna array; respective antenna feeders connecting said every two elements together being designed to have substantially the same length; and a number of pairs of impedance matching stubs, the stubs of each pair being parallely connected at substantially equally spaced points on either side of the center of respective antenna feeders in the lengthwise direction thereof, said stubs being so arranged and having a length such that incoming waves are reradiated either straight backward or in an opposite direction to that in which they are received.
Claim 2
Dependent Claim
123 words
A Van-Atta array antenna device comprising: a plurality of antenna elements juxtaposed at substantially equal distances from each other; every two of said elements being disposed in a symmetrical relationship with respect to the center of said aNtenna array; respective antenna feeders connecting said every two elements together being designed to have substantially the same length; and a number of pairs of impedance matching stubs, the stubs of each pair being parallely connected at substantially equally spaced points on either side of the center of respective antenna feeders in the lengthwise direction thereof, said stubs being so arranged and having a length such that incoming waves are reradiated either straight backward or in an opposite direction to that in which they are received.
Claim 3
Dependent Claim
198 words
A Van-Atta array antenna device comprising: a plurality of equally spaced antenna elements; feeders of substantially equal length interconnecting respective pairs of said antenna elements which are symmetrically located with respect to the center of the antenna array; and a number of impedance matching stubs, each being connected to the corresponding feeder and having such a length that the incoming waves are reradiated either straight backward or in an opposite direction to that in which they are received, without changing the characteristic impedance of said feeders, the length l'' of said stubs, when the characteristic impedance thereof is assumed to be Zo /2 and the transmission loss of the feeders is neglected, being set to satisfy the equation: Zr + Zm - jZo cot Beta ((l/2) + l'') (R11 + R12) + J(R11 + R12) Zr - Zm + jZo tan Beta .(l/2) (R11 - R12) - J(R11 - R12) where: Zr the impedance of said antenna elements, Zm the mutual impedance between said antenna elements, Zo the characteristic impedance of said feeders, R11 the real part of said Zr, R12 the real part of said Zm, Beta the phase constant, and l the length of said feeders.
Claim 4
Dependent Claim
198 words
A Van-Atta array antenna device comprising: a plurality of equally spaced antenna elements; feeders of substantially equal length interconnecting respective pairs of said antenna elements which are symmetrically located with respect to the center of the antenna array; and a number of impedance matching stubs, each being connected to the corresponding feeder and having such a length that the incoming waves are reradiated either straight backward or in an opposite direction to that in which they are received, without changing the characteristic impedance of said feeders, the length l'' of said stubs, when the characteristic impedance thereof is assumed to be Zo /2 and the transmission loss of the feeders is neglected, being set to satisfy the equation: Zr + Zm - jZo cot Beta ((l/2) + l'') (R11 + R12) + J(R11 + R12) Zr - Zm + jZo tan Beta .(l/2) (R11 - R12) - J(R11 - R12) where: Zr the impedance of said antenna elements, Zm the mutual impedance between said antenna elements, Zo the characteristic impedance of said feeders, R11 the real part of said Zr, R12 the real part of said Zm, Beta the phase constant, and l the length of said feeders.
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) | 1976-04-30 | 1976-10-30 | 1977-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-30 | 1980-10-30 | 1981-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-30 | 1984-10-30 | 1985-05-01 | $7700.00 | Window Closed / Lapsed |