US3710340A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Small, broadband, unidirectional antenna
Assignee: Jfd Electronics Corp
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Filing: 1971-10-13
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Granted: 1973-01-09
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Expires: 1991-10-13
Abstract
Abstract A non-resonant antenna structure for the reception and/or radiation of electromagnetic waves in a unidirectional manner over a broad frequency band. The structure consists of two resonant elements of dual type fed simultaneously from the same transmission line. The resonant elements are adjusted so that the image impedance of the composite two-port structure is nearly constant and resistive over a very wide frequency band. One port is terminated in a resistor approximately equal in value to the image impedance. As a result, the impedance observed at the other port is also very nearly a constant resistance. In a given plane through the antenna one element has an omnidirectional radiation pattern; the other, a typical figure-of-eight dipole pattern. Proper adjustment of feeder impedance relative to the impedances of the individual elements leads to a unidirectional pattern with high front-to-back ratio over the operating band. Since achievement of the above conditions is possible at frequencies below the first resonant frequency of either element, the antenna dimensions may be small compared to the wavelength, particularly at the lower end of the operating band.
Inventors
- 👤 P Mayes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:43
CPC Classifications
H; H01; H01Q; H01Q21/00; H01Q21/29
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
157 words
An antenna structure comprising: a ground plane having an aperture; an open ended enclosure with conducting walls attached to the ground plane in a manner to enclose the slot on one side of said ground plane, whereby the portion of said ground plane surrounding said slot engages the open end of the enclosure; a single-conductor transmission line suspended a spaced distance above said slot and being substantially parallel to the ground plane and aligned transverse to one center line of said slot in the vicinity of the intersection of the center-line of the slot; a resistive termination electrically connected between the line and the ground plane being provided near one end of the line; a monopole of conducting material electrically connected to said line near the point where the line passes over the slot; terminal means at the other end of the line for connecting the antenna to transmission means for coupling to a transmitter or receiver.
Claim 2
Dependent Claim
157 words
An antenna structure comprising: a ground plane having an aperture; an open ended enclosure with conducting walls attached to the ground plane in a manner to enclose the slot on one side of said ground plane, whereby the portion of said ground plane surrounding said slot engages the open end of the enclosure; a single-conductor transmission line suspended a spaced distance above said slot and being substantially parallel to the ground plane and aligned transverse to one center line of said slot in the vicinity of the intersection of the center-line of the slot; a resistive termination electrically connected between the line and the ground plane being provided near one end of the line; a monopole of conducting material electrically connected to said line near the point where the line passes over the slot; terminal means at the other end of the line for connecting the antenna to transmission means for coupling to a transmitter or receiver.
Claim 3
Dependent Claim
14 words
The antenna of claim 1 wherein the slot has the shape of a rectangle.
Claim 4
Dependent Claim
13 words
The antenna of claim 1 wherein the slot has a bitriangular (bow-tie) shape.
Claim 5
Dependent Claim
12 words
The antenna of claim 1 wherein the monopole has a cylindrical shape.
Claim 6
Dependent Claim
12 words
The antenna of claim 1 wherein the monopole has a conical shape.
Claim 7
Dependent Claim
21 words
The antenna of claim 4 wherein the monopole is constructed of a plurality of wires arranged to define the given shape.
Claim 8
Dependent Claim
29 words
The antenna of claim 6 wherein intersecting wires are provided to join said plurality of wires to cause said plurality of wires to retain the shape of the monopole.
Claim 9
Dependent Claim
13 words
The antenna of claim 4 where monopole is formed of a wire mesh.
Claim 10
Dependent Claim
15 words
The antenna of claim 1 wherein the ground plane is the surface of the earth.
Claim 11
Dependent Claim
20 words
The antenna of claim 1 wherein the ground plane is a conducting mesh positioned near the surface of the earth.
Claim 12
Dependent Claim
19 words
The antenna of claim 1 wherein the ground plane is the metallic skin of an aircraft, rocket, or vehicle.
Claim 13
Dependent Claim
16 words
The antenna of claim 1 wherein the ground plane is constructed of a plurality of wires.
Claim 14
Dependent Claim
29 words
The antenna of claim 1 wherein the transmission line is a conducting strip supported by a slab of dielectric material positioned between said ground plane and said conducting strip.
Claim 15
Dependent Claim
99 words
An antenna comprising: a ground plane; an aperture in said ground plane; an elongated conductive strip positioned above said ground plane and overlying said slot; a hollow open ended conductive enclosure positioned beneath said slot with said ground plane overlying the open end of said enclosure; a monopole having its first end electrically coupled to said conductive strip; a resistive element coupled between one end of said strip and said ground plane; means provided on said ground plane and the opposite end of said strip and said ground plane for coupling said antenna to a transmitting or receivinG instrument.
Claim 16
Dependent Claim
99 words
An antenna comprising: a ground plane; an aperture in said ground plane; an elongated conductive strip positioned above said ground plane and overlying said slot; a hollow open ended conductive enclosure positioned beneath said slot with said ground plane overlying the open end of said enclosure; a monopole having its first end electrically coupled to said conductive strip; a resistive element coupled between one end of said strip and said ground plane; means provided on said ground plane and the opposite end of said strip and said ground plane for coupling said antenna to a transmitting or receivinG instrument.
References Cited (Backward Citations)
US3631500A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |