US3838429A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Miniaturized transmission line top loaded monopole antenna
Assignee: United States Department of the Army
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Filing: 1973-08-03
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Granted: 1974-09-24
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Expires: 1993-08-03
Abstract
Abstract A miniaturized antenna having high radiation efficiency consists essentially of an open circuit transmission line top-loading a short monopole over a metal ground plane. The currents in the two sides of the transmission line, being oppositely directed, tend to cancel each other''s effect in the distant field. Thus, only the short vertical monopole contributes to the distant field radiation. The omnidirectional monopole is a constant current radiating element operating at near RF ground potential (high current, low impedance).
Inventors
- 👤 F Reggia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:27
CPC Classifications
H; H01; H01Q; H01Q9/00; H01Q9/04; H01Q9/30; H01Q9/32; H01Q9/36
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
155 words
A miniaturized antenna structure comprising: a metal ground plane member; a hollowed cylindrical monopole perpendicularly disposed and electrically connected at one end thereof to the ground plane member for radiating electromagnetic energy therefrom; a printed circuit board located at a second end of the monopole, and in parallel spaced relation to the ground plane member, the printed circuit board including an insulator substrate and a spiral conductor transmission line formed thereon, the transmission line having a first end short circuited to the monopole while an opposite second end is open circuited; and a coaxial cable extending through the cylindrical monopole, the cable being connected to an r.f source at one end thereof, an outer cable conductor connected at an opposite end to the cylindrical monopole, an inner cable conductor connected between the source and a point along the transmission line for producing preselected transmission line impedance, whereby the monopole radiates energy in an onmidirectional pattern.
Claim 2
Dependent Claim
155 words
A miniaturized antenna structure comprising: a metal ground plane member; a hollowed cylindrical monopole perpendicularly disposed and electrically connected at one end thereof to the ground plane member for radiating electromagnetic energy therefrom; a printed circuit board located at a second end of the monopole, and in parallel spaced relation to the ground plane member, the printed circuit board including an insulator substrate and a spiral conductor transmission line formed thereon, the transmission line having a first end short circuited to the monopole while an opposite second end is open circuited; and a coaxial cable extending through the cylindrical monopole, the cable being connected to an r.f source at one end thereof, an outer cable conductor connected at an opposite end to the cylindrical monopole, an inner cable conductor connected between the source and a point along the transmission line for producing preselected transmission line impedance, whereby the monopole radiates energy in an onmidirectional pattern.
Claim 3
Dependent Claim
48 words
The subject matter of claim 1 wherein the printed circuit board includes a second spiral conductor, generally concentric with the first, and further means are provided to connect the inner cable conductor with a point along the transmission line for effecting multiple frequency operation of the antenna structure.
Claim 4
Dependent Claim
30 words
The subject matter as defined in claim 1 together with a variable capacitor connected across the open circuited end of the transmission line for tuning a preselected frequency of operation.
Claim 5
Dependent Claim
144 words
A small antenna structure comprising: a ground plane member; monopole radiating means perpendicular disposed and electrically connected at one end thereof to the ground plane member for radiating electromagnetic energy therefrom; a spiral transmission line located at a second end of the radiating means, and in parallel spaced relation to the ground plane member, the transmission line having a first end short circuited to the radiating means while an opposite second end is open circuited; and feed line means connected at a first end to an r.f. input source, a second end connected to a point along the transmission line for producing a preselected transmission line impedance; a second spiral transmission line positioned concentric with the first transmission line; means for connecting the feed line means to a point along the second spiral transmission line for effecting multiple frequency operation of the antenna structure.
Claim 6
Dependent Claim
144 words
A small antenna structure comprising: a ground plane member; monopole radiating means perpendicular disposed and electrically connected at one end thereof to the ground plane member for radiating electromagnetic energy therefrom; a spiral transmission line located at a second end of the radiating means, and in parallel spaced relation to the ground plane member, the transmission line having a first end short circuited to the radiating means while an opposite second end is open circuited; and feed line means connected at a first end to an r.f. input source, a second end connected to a point along the transmission line for producing a preselected transmission line impedance; a second spiral transmission line positioned concentric with the first transmission line; means for connecting the feed line means to a point along the second spiral transmission line for effecting multiple frequency operation of the antenna structure.
Claim 7
Dependent Claim
26 words
The subject matter of claim 4 together with a second feed line means for connecting the source to a point along the second spiral transmission line.
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) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |