US4295144A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Feed system for a circularly polarized tetra-coil antenna
Assignee: SAC Corp
•
Filing: 1980-03-31
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Granted: 1981-10-13
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Expires: 2000-03-31
Abstract
Abstract A feed system for a helical CP antenna features folded belt or phasing lines to reduce space. This reduces icing and wind loading problems. If two belt lines are used, they can be placed diametrically opposite each other to reduce mutual coupling.
Inventors
- 👤 Joseph J. Matta
- 👤 Andrej Skalina
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:19
CPC Classifications
H; H01; H01Q; H01Q1/00; H01Q1/36; H01Q1/362
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
87 words
An antenna comprising a central conductive mast, at least first and second conducting helices disposed about said mast, a conductive housing disposed proximate an end of said helices, a coaxial transmission line disposed within said mast, the inner conductor of said line extending into said housing and being coupled to said first helix, and a first belt line disposed in said housing and coupled between said helices and having a selected length to provide a selected phase shift between said helices and being folded to conserve space.
Claim 2
Dependent Claim
87 words
An antenna comprising a central conductive mast, at least first and second conducting helices disposed about said mast, a conductive housing disposed proximate an end of said helices, a coaxial transmission line disposed within said mast, the inner conductor of said line extending into said housing and being coupled to said first helix, and a first belt line disposed in said housing and coupled between said helices and having a selected length to provide a selected phase shift between said helices and being folded to conserve space.
Claim 3
Dependent Claim
28 words
An antenna as claimed in claim 1, further comprising third and fourth conducting helices disposed about said mast, said inner conductor being coupled to all of said helices.
Claim 4
Dependent Claim
41 words
An antenna as claimed in claim 2, further comprising a second belt line disposed in said housing and coupled between said third and fourth helices to provide a selected phase shift therebetween, said second belt line being folded to conserve space.
Claim 5
Dependent Claim
33 words
An antenna as claimed in claim 3, wherein said first and third helices are adjacent each other, and further comprising a balun coupled between said transmission line and said first and third helices.
Claim 6
Dependent Claim
17 words
An antenna as claimed in claim 3, wherein said first and third helices are opposite each other.
Claim 7
Dependent Claim
47 words
An antenna as claimed in claim 2, further comprising second and third belt lines disposed in said housing and coupled between said first and third and said third and fourth helices respectively for providing selected phase shifts therebetween respectively, said belt lines being folded to conserve space.
Claim 8
Dependent Claim
39 words
An antenna as claimed in claims 1 or 3, wherein said housing is circular and said belt lines are arcuate and evenly spaced from said housing to provide a constant characteristic impedance along the length of any belt line.
Claim 9
Dependent Claim
21 words
An antenna as claimed in claim 1, wherein said first belt line lies in a cylindrical surface coaxial with said mast.
References Cited (Backward Citations)
US3906509A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-12 | 1985-04-13 | 1985-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-12 | 1989-04-13 | 1989-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-12 | 1993-04-13 | 1993-10-13 | $7700.00 | Window Closed / Lapsed |