US3701157A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helicopter uhf antenna system for satellite communications
Assignee: United States Department of the Air Force
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Filing: 1971-06-03
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Granted: 1972-10-24
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Expires: 1991-06-03
Abstract
Abstract A UHF antenna comprising crossed dipoles in the shape of drooped bow ties, encased by a polyester fiberglass laminated cone, positioned above and rotating with the blades of the helicopter, and orthogonally fed by a coaxial transmission line running through the hollow rotating mast provides an antenna for overhead signal transmission and reception. A coaxial rotary joint is placed inside the mast at the lower end to make a rotating electrical connection with the feed line.
Inventors
- 👤 Jerome W Uhrig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:09
CPC Classifications
H; H01; H01Q; H01Q1/00; H01Q1/27; H01Q1/28; H01Q1/282; H01Q1/40; H01Q21/00; H01Q21/24; H01Q21/26; H01Q9/00; H01Q9/04; H01Q9/16; H01Q9/28; H01Q9/285
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
82 words
An antenna system, for a helicopter having a hollow rotor mast, for communicating via overhead satellite link, comprising: a. dual crossed bow tie radiating elements positioned on the top of the said rotor mast and rotating therewith; b. means cooperating with the interior of the said hollow mast and rotating therewith for orthogonally feeding the said radiating elements for circularly polarized radiation; and c. means for electrical coupling from exterior the said mast to the means for orthogonally feeding the radiating elements.
Claim 2
Dependent Claim
82 words
An antenna system, for a helicopter having a hollow rotor mast, for communicating via overhead satellite link, comprising: a. dual crossed bow tie radiating elements positioned on the top of the said rotor mast and rotating therewith; b. means cooperating with the interior of the said hollow mast and rotating therewith for orthogonally feeding the said radiating elements for circularly polarized radiation; and c. means for electrical coupling from exterior the said mast to the means for orthogonally feeding the radiating elements.
Claim 3
Dependent Claim
182 words
An antenna system for communicating with a conventional communication set from a helicopter having a hollow rotor mast via overhead satellite link, the said communication set having a determined connecting impedance comprising: a. drooped, dual, crossed bow tie antenna radiating elements, quadrature spaced, enclosed in an insulating protective cover; b. means including a hollow tube cooperating with the said enclosed antenna radiating elements and the said rotor mast for axially positioning the antenna in fixed relationship on top of the rotor mast; c. means cooperating with the said antenna elements extending into the said hollow tube for orthogonally coupling the said antennA elements and providing a common point of signal coupling; d. means including an electrical quarter wavelength of coaxial cable for matching the electrical impedance at the said common signal coupling point to provide the said connecting impedance of the communication set, the said matching means being contained within the hollow rotor mast; and e. means including a coaxial rotary joint positioned at the bottom of the said rotor mast, for coupling the said communication set to the said matching means.
Claim 4
Dependent Claim
182 words
An antenna system for communicating with a conventional communication set from a helicopter having a hollow rotor mast via overhead satellite link, the said communication set having a determined connecting impedance comprising: a. drooped, dual, crossed bow tie antenna radiating elements, quadrature spaced, enclosed in an insulating protective cover; b. means including a hollow tube cooperating with the said enclosed antenna radiating elements and the said rotor mast for axially positioning the antenna in fixed relationship on top of the rotor mast; c. means cooperating with the said antenna elements extending into the said hollow tube for orthogonally coupling the said antennA elements and providing a common point of signal coupling; d. means including an electrical quarter wavelength of coaxial cable for matching the electrical impedance at the said common signal coupling point to provide the said connecting impedance of the communication set, the said matching means being contained within the hollow rotor mast; and e. means including a coaxial rotary joint positioned at the bottom of the said rotor mast, for coupling the said communication set to the said matching means.
References Cited (Backward Citations)
US3390393A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |