Patent US3573839A successfully refreshed from Google Patents.
US3573839A
Expired / Lapsed
US
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Foreshortened log-periodic antenna employing inductively loaded and folded dipoles
Assignee: Individual
•
Filing: 1969-04-24
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Granted: 1971-04-06
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Expires: 1989-04-24
Abstract
Abstract Some of the lower frequency elements of this planar dipole log periodic antenna are inductively loaded to reduce the size thereof and others of said lower frequency elements are both loaded and folded, and in addition the dipoles are provided with a mounting and supporting boom which also functions as a balanced low impedance transmission line.
Inventors
- 👤 James C Parker Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:57
CPC Classifications
H; H01; H01Q; H01Q11/00; H01Q11/02; H01Q11/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
68 words
A compact and easily portable planar dipole-type log periodic antenna comprising a plurality of spaced dipole elements which are tapered in electrical length and in spacing between adjacent elements and a feedline for said elements in which some of the lower frequency elements thereof are inductively loaded linear dipoles and in addition one or more of the more heavily loaded dipole elements are inductively loaded and folded dipoles.
Claim 2
Dependent Claim
68 words
A compact and easily portable planar dipole-type log periodic antenna comprising a plurality of spaced dipole elements which are tapered in electrical length and in spacing between adjacent elements and a feedline for said elements in which some of the lower frequency elements thereof are inductively loaded linear dipoles and in addition one or more of the more heavily loaded dipole elements are inductively loaded and folded dipoles.
Claim 3
Dependent Claim
18 words
The antenna of claim 1 in which said loaded dipole elements are loaded by an electrically conductive helix.
Claim 4
Dependent Claim
29 words
The antenna of claim 1 wherein all of said lower frequency elements are the same physical length but are tapered in electrical length according to the log periodic relationship.
Claim 5
Dependent Claim
35 words
The antenna of claim 1, wherein said loaded dipole elements each consist of a single tubular member having at least a portion thereof formed of an electrically insulating material surrounded by a helical slow-wave structure.
Claim 6
Dependent Claim
54 words
The antenna of claim 4 in which all of said dipole elements are supported on a pair of back-to-back metal channels mounted one above the other, the space between said channels forming a low impedance transmission line, said feedline being a coaxial feedline connected to said pair of channels to form an unbalanced-to-balanced transformation.
Claim 7
Dependent Claim
32 words
The antenna of claim 1 wherein said loaded dipole elements are each of substantially uniform cross section throughout the length thereof and said portion is the major portion of said dipole element.
References Cited (Backward Citations)
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US3363254A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |