US3681772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modulated arm width spiral antenna
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1970-12-31
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Granted: 1972-08-01
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Expires: 1990-12-31
Abstract
Abstract A multi-arm spiral antenna which allows unlimited broadband operation with dual senses of circular polarization. The antenna comprises spiral arms having width variations which are logperiodically scaled to produce local reflection (stopband) regions along the arms. The position of the stop-band regions is a function of the period and amplitude of width variations. Arm currents are produced by excitation of the antenna. These currents are reflected by the stopband regions. The relative phase of the reflected currents is a function of the relative scaling of the arms.
Inventors
- 👤 Paul G Ingerson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:21
CPC Classifications
H; H01; H01Q; H01Q11/00; H01Q11/02; H01Q11/08; H01Q11/083; H01Q1/00; H01Q1/36; H01Q1/38
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
97 words
A multi-arm spiral antenna capable of radiating circularly polarized electromagnetic energy with opposite senses of polarization, said antenna comprising: a. at least two spiral arms, each arm consisting of a plurality of interconnected cells, each cell consisting of a wide and a narrow section along the length of its arm, the transition between adjacent wide and narrow sections being relatively abrupt, whereby to reflect electromagnetic energy, the sections of each cell increasing in length as the distance from the center increases, and b. means for feeding said arms at the center of the spiral with electromagnetic energy.
Claim 2
Dependent Claim
97 words
A multi-arm spiral antenna capable of radiating circularly polarized electromagnetic energy with opposite senses of polarization, said antenna comprising: a. at least two spiral arms, each arm consisting of a plurality of interconnected cells, each cell consisting of a wide and a narrow section along the length of its arm, the transition between adjacent wide and narrow sections being relatively abrupt, whereby to reflect electromagnetic energy, the sections of each cell increasing in length as the distance from the center increases, and b. means for feeding said arms at the center of the spiral with electromagnetic energy.
Claim 3
Dependent Claim
16 words
The antenna of claim 1 wherein: the ratio of the lengths of adjacent arm-cells is constant.
Claim 4
Dependent Claim
20 words
The antenna of claim 2 wherein: the ratio of the widths of the wide section of adjacent arm-cells is constant.
Claim 5
Dependent Claim
27 words
The antenna of claim 3 wherein: the ratios of the widths of the wide sections of adjacent cells and the cell lengths of adjacent cells are equal.
Claim 6
Dependent Claim
21 words
The antenna of claim 3 wherein: the ratio of the width of the narrow section of adjacent arm cells is constant.
Claim 7
Dependent Claim
24 words
The antenna of claim 4 wherein: the ratios of the narrow sections of each cell are equal to the ratios of the cell lengths.
Claim 8
Dependent Claim
13 words
The antenna of claim 1 wherein: the said spiral is an equiangular spiral.
Claim 9
Dependent Claim
13 words
The antenna of claim 7 wherein: the number of said arms is four.
Claim 10
Dependent Claim
14 words
The antenna of claim 8 wherein: the arms are identical in size and shape.
Claim 11
Dependent Claim
31 words
An antenna as defined in claim 1 wherein the spacing between adjacent ones of said arms is nonuniform, thereby to provide a change of impedance in a direction along said arms.
Claim 12
Dependent Claim
18 words
An antenna as defined in claim 1 wherein said arms are disposed on the surface of a cone.
References Cited (Backward Citations)
US3454951A
Cited
US3562756A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |