US4217591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High frequency roll-bar loop antenna
Assignee: United States Department of the Army
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Filing: 1979-08-27
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Granted: 1980-08-12
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Expires: 1999-08-27
Abstract
Abstract A vehicular mounted loop antenna which operates as an NVIS radio communicon antenna over one range of frequencies and as a vertically polarized whip antenna over another range of frequencies corresponding to the frequency range of a radio communication set equipped with a conventional whip antenna. A coupling loop of variable area and a transmitting loop are positioned in a common vertical plane on a horizontally disposed base member, with the coupling loop positioned within the transmitting loop. A variable capacitor is in circuit with, and is an integral element of, the transmitter loop to provide resonance over the desired operating frequency range.
Inventors
- 👤 Watson P. Czerwinski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:17
CPC Classifications
H; H01; H01Q; H01Q1/00; H01Q1/27; H01Q1/32; H01Q1/325; H01Q1/3275; H01Q7/00; H01Q9/00; H01Q9/04; H01Q9/30; H01Q9/42
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
116 words
A loop antenna for operation on a moving vehicle comprising: a metallic base mounted longitudinally on top of said vehicle; a vertically mounted elongated, metallic loop element having one end affixed to said metallic base; a variable capacitor in series with the other end of said metallic loop element and said metallic base and in conjunction with said metallic base and said elongated metallic loop element forming a closed transmitting loop; a coupling loop of variable area, coplanar with and at no point exterior to, said closed transmitting loop and inductively coupled thereto; and an input terminal electrically connected to said coupling loop for feeding a signal into or removing a signal from said coupling loop.
Claim 2
Dependent Claim
116 words
A loop antenna for operation on a moving vehicle comprising: a metallic base mounted longitudinally on top of said vehicle; a vertically mounted elongated, metallic loop element having one end affixed to said metallic base; a variable capacitor in series with the other end of said metallic loop element and said metallic base and in conjunction with said metallic base and said elongated metallic loop element forming a closed transmitting loop; a coupling loop of variable area, coplanar with and at no point exterior to, said closed transmitting loop and inductively coupled thereto; and an input terminal electrically connected to said coupling loop for feeding a signal into or removing a signal from said coupling loop.
Claim 3
Dependent Claim
49 words
The loop antenna of claim 1 wherein said coupling loop is partially comprised of a coaxial cable, slidably mounted on, and electrically connected to, said metallic base thereby providing said coupling loop with a variable area so as to permit adjustment to the input impedance of said loop antenna.
Claim 4
Dependent Claim
14 words
The loop antenna of claim 2 wherein said metallic base comprises a U-shaped channel.
Claim 5
Dependent Claim
16 words
The loop antenna of claim 3 wherein said closed transmitting loop is approximately rectangular in shape.
References Cited (Backward Citations)
US2431124A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-12 | 1984-02-11 | 1984-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-12 | 1988-02-11 | 1988-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-12 | 1992-02-11 | 1992-08-12 | $7700.00 | Window Closed / Lapsed |