Patent US3696437A successfully refreshed from Google Patents.
US3696437A
Expired / Lapsed
US
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Broadside log periodic antenna
Assignee: Jfd Electronics Corp
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Filing: 1970-08-27
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Granted: 1972-10-03
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Expires: 1990-08-27
Abstract
Abstract This invention teaches an antenna array of the broadside type in which dipoles of differing electrical lengths are stacked vertically above and below an imaginary plane with electrical lengths increasing with increasing distance in moving above and below the imaginary plane. The antenna has symmetry in that for each dipole of the array below the imaginary plane, for example, there is a dipole of substantially equal electrical length and spacing approximately the same distance above the imaginary plane. Transposed feeder harness means are employed for joining adjacent dipoles and common output (input) terminals are provided in a position substantially at the location of the imaginary plane. Directional characteristics are obtained by means of Veeing the dipole arms and/or providing a vertically aligned ground screen positioned behind the antenna stack array. In another embodiment a similar array may be positioned immediately behind the first array in place of the ground screen. Directional characteristics may be obtained through coupling an output (input) utilization means to one and then the other of the arrays which are coupled at their feed terminals by means of a transposed feeder section. The array may also be joined with a conventional endfire array, for example, to form a broadside VHF endfire array and an endfire UHF array or conversely, a broadside UHF array and an endfire VHF array. Omnidirectional characteristics may be introduced if such an application is either desired or required by bending or otherwise forming the dipole arms so as to provide a substantially U-shaped configuration for each dipole. As another embodiment the ground screen may be replaced by parasitic elements arranged in a vertically stacked array with the parasitic element being provided for each dipole in the broadside array and being positioned in substantially behind its associated dipole.
Inventors
- 👤 Ronald D Grant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:50
CPC Classifications
H; H01; H01Q; H01Q21/00; H01Q21/30; H01Q11/00; H01Q11/02; H01Q11/10
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
178 words
An antenna array comprised of elongated support means; a plurality of active elements positioned at spaced intervals along said support means; a pair of feed terminals positioned intermediate the ends of said support means for coupling energy between said active elements and utilization means; said active elements being comprised of a plurality of dipoles; half of said dipoles being positioned at predetermined spaced intervals along said support means between said feed terminals and one end of said support means; each of said dipoles being comprised of first and second arms lying on opposite sides of said support means; a transposed feeder harness coupling the inboard ends of said dipoles to said feed terminals; the remaining half of said dipoles being positioned along said support means between said feed terminals and the opposite end of said support means to form an antenna array which is substantially symmetrical about an imaginary horizontal plane passing through the point of connection of said feed terminals and said feeder harness; said transposed feeder harness further coupling the remaining dipoles to said feed terminals.
Claim 2
Dependent Claim
178 words
An antenna array comprised of elongated support means; a plurality of active elements positioned at spaced intervals along said support means; a pair of feed terminals positioned intermediate the ends of said support means for coupling energy between said active elements and utilization means; said active elements being comprised of a plurality of dipoles; half of said dipoles being positioned at predetermined spaced intervals along said support means between said feed terminals and one end of said support means; each of said dipoles being comprised of first and second arms lying on opposite sides of said support means; a transposed feeder harness coupling the inboard ends of said dipoles to said feed terminals; the remaining half of said dipoles being positioned along said support means between said feed terminals and the opposite end of said support means to form an antenna array which is substantially symmetrical about an imaginary horizontal plane passing through the point of connection of said feed terminals and said feeder harness; said transposed feeder harness further coupling the remaining dipoles to said feed terminals.
Claim 3
Dependent Claim
47 words
The antenna array of claim 1 wherein the first arms and the second arms of all of said dipoles lie substantially in first and second respective planes which are parallel to said support means; and which intersect forming an angle within the range from 40* to 180*.
Claim 4
Dependent Claim
23 words
The antenna array of claim 1 further comprising reflection means positioned adjacent said support means for enhancing the directional characteristics of said array.
Claim 5
Dependent Claim
22 words
The antenna array of claim 3 wherein said reflection means is comprised of a substAntially planar conductive screen having a grid-like pattern.
Claim 6
Dependent Claim
91 words
The array of claim 3 wherein said reflection means is comprised of second elongated support means positioned side by side with respect to said first support means; a plurality of parasitic elements positioned at spaced intervals along said second support means and being secured to said support means at a point substantially equidistant from their outboard ends; the spacing between adjacent parasitic elements and the electrical lengths of said parasitic elements being selected to provide a symmetrical pattern about said feed terminal point comparable to the symmetrical pattern of said dipoles.
Claim 7
Dependent Claim
29 words
The antenna array of claim 5 wherein each of said parasitic elements is positioned along said second support means so as to be substantially coplanar with an associated dipole.
Claim 8
Dependent Claim
36 words
The antenna array of claim 5 wherein each of said parasitic elements is bent at its point of securement to said second support means to form an angle lying in the range from 40* to 180*.
Claim 9
Dependent Claim
39 words
The antenna array of claim 7 wherein the dipoles and parasitic elements are aligned so that one imaginary plane defines the common disector of the angles formed by the first and second arms of said dipoles and parasitic elements.
Claim 10
Dependent Claim
43 words
The antenna array of claim 1 wherein said electrical lengths of the longest dipoles are substantially equal to n/2 where n is any real integer and lambda is the wavelength of the lowest frequency for the operating frequency range of the antenna array.
Claim 11
Dependent Claim
106 words
The antenna array of claim 9 wherein the ratio of the electrical lengths of any dipole of said selected dipoles is given by the formula 1n 1/1n Tau where 1n is the electrical length of the larger dipole and 1n+1 is the electrical length of the smaller adjacent dipole, and n is the nth arm running in an order from the dipole furthest from the feed terminals toward said feed terminals, and Tau is a constant in the range from 0.78 to 0.99; the ratio of the electrical lengths of said remaining dipoles being determined in the same manner as that employed for the selected dipoles.
Claim 12
Dependent Claim
75 words
The antenna array of claim 9 wherein the spacing between adjacent dipoles measured along said first support means is determined by the formula dn 1/dn Tau where dn is the spacing between the dipole having the electrical length 1n and the adjacent larger dipole; dn 1 is the spacing between the dipole having the electrical length 1n and the adjacent smaller dipole and Tau is a constant lying in the range from 0.78 to 0.99.
Claim 13
Dependent Claim
128 words
The antenna array of claim 5 wherein the ratio of the electrical lengths of any parasitic element from the feed terminals to one end of said array is given by the formula 1n 1/1n Tau where 1n is the electrical length of the larger parasitic element and 1n 1 is the electrical length of the smaller adjacent parasitic element, and n is the nth arm running in an order from the parasitic element furthest from the feed terminals toward said feed terminals, and Tau is a constant in the range from 0.78 to 0.99; the ratio of the electrical lengths of the remaining parasitic elements being determined in the same manner as that employed for the parasitic elements between said feed terminals and one end of said array.
Claim 14
Dependent Claim
46 words
The antenna array of claim 12 wherein the electrical length of the longest parasitic element ln at either outer end of the array is determined by the equation l1 L(1+0.05L) where L is the electrical length of the longest dipole associated with the longest parasitic element.
Claim 15
Dependent Claim
71 words
The antenna array of claim 5 wherein said second elongated support means is bent at a point near the feed Terminals of said array so that the upper and lower halves thereof form equal angles with said first support means so as to space each parasitic element a distance s away from its associated dipole determined by the equation where lambda wavelength to which the associated dipole is attuned to resonate.
Claim 16
Dependent Claim
21 words
The antenna array of claim 5 wherein said parasitic elements are V''d in a direction opposite from that of said dipoles.
Claim 17
Dependent Claim
31 words
The antenna array of claim 1 wherein the dipole first and second arms are curved so that the outboard ends thereof extend in a direction generally perpendicular to the inboard ends.
Claim 18
Dependent Claim
48 words
The antenna array of claim 16 wherein the electrical lengths of the first and second arms of the longest dipole are each in the range from 0.4 lambda to 0.6 lambda where lambda is the wavelength of the lowest frequency in the operating frequency range of the array.
Claim 19
Dependent Claim
53 words
The antenna array of claim 1 wherein the first and second arms of each dipole are comprised of an inboard section and an outboard section; said inboard and outboard sections being substantially straight; integral with one another and forming an angle at their juncture point lying in the range from 40* to 180*.
Claim 20
Dependent Claim
86 words
The antenna array of claim 18 wherein the ratio of lengths of each outboard section lout to its associated inboard section lin is given by the equation lout Klin where K is a constant lying in the range from 1.5 < or = K < or = 3.0; the total electrical length of the longest dipole arms each being in the range from 0.4 lambda to 0.6 lambda where lambda is the wavelength of the lowest frequency in the operating frequency range of the antenna array.
Claim 21
Dependent Claim
70 words
A composite antenna array comprised of first and second antenna arrays of the type described in claim 1 and being arranged so that their support means are arranged substantially in spaced parallel fashion and directions of maximum gain are coincident and point in opposite directions; a transposed feeder section coupling their feed terminals; the feed terminals of one of said arrays being adapted to be coupled to suitable utilization means.
Claim 22
Dependent Claim
71 words
A composite antenna array comprised of first and second antenna arrays of the type described in claim 1 and being arranged so that their support means are arranged substantially in spaced parallel fashion and their directions of maximum gain are coincident and point in the same direction; transposed feeder section coupling their feed terminals; the feed terminals of one of said arrays being adapted to be coupled to suitable utilization means.
Claim 23
Dependent Claim
69 words
A composite antenna array comprised of first and second antenna arrays of the type described in claim 1 and being arranged so that their support means are arranged substantially in spaced parallel fashion and their directions of maximum gain are coincident and point in opposite directions; a transposed feeder section coupling their feed terminals; means coupled between said feed terminals for altering the directional characteristic of the composite array.
Claim 24
Dependent Claim
30 words
The composite array of claim 22 wherein said switching means is comprised of two-position switch means for coupling one or the other of said feed terminals to suitable utilization means.
Claim 25
Dependent Claim
75 words
The composite array of claim 22 wherein said switching means is comprised of bandpass filter means coupled between the feed terminals of said first and second arrays for passing the signals of one of said arrays which lie in one frequency band while attenuating the signals from the remaining array which lie in said one frequency band; said one frequency band being smaller than the frequency range for which said arrays are designed to operate.
Claim 26
Dependent Claim
207 words
An antenna array comprised of elongated support means; a plurality of active elements positioned at spaced intervals along said suPport means; a pair of feed terminals positioned intermediate the ends of said support means for coupling energy between said active elements and utilization means; said active elements being comprised of a plurality of dipoles; half of said dipoles being positioned at predetermined spaced intervals along said support means between said feed terminals and one end of said support means; each of said dipoles being comprised of first and second arms lying on opposite sides of said support means; a transposed feeder harness coupling the inboard ends of said half of said dipoles to said feed terminals; the remaining half of said dipoles being positioned at predetermined spaced intervals along said support means between said feed terminals and the opposite end of said support means to form an antenna array which is substantially symmetrical about a horizontal plane passing through the point of connection of said feed terminals and said feed harness whereby associated dipoles positioned on opposite sides of said feed terminals are separated from the feed terminals by equal distances; said transposed feeder harness further coupling the remaining half of said dipoles to said feed terminals.
Claim 27
Dependent Claim
207 words
An antenna array comprised of elongated support means; a plurality of active elements positioned at spaced intervals along said suPport means; a pair of feed terminals positioned intermediate the ends of said support means for coupling energy between said active elements and utilization means; said active elements being comprised of a plurality of dipoles; half of said dipoles being positioned at predetermined spaced intervals along said support means between said feed terminals and one end of said support means; each of said dipoles being comprised of first and second arms lying on opposite sides of said support means; a transposed feeder harness coupling the inboard ends of said half of said dipoles to said feed terminals; the remaining half of said dipoles being positioned at predetermined spaced intervals along said support means between said feed terminals and the opposite end of said support means to form an antenna array which is substantially symmetrical about a horizontal plane passing through the point of connection of said feed terminals and said feed harness whereby associated dipoles positioned on opposite sides of said feed terminals are separated from the feed terminals by equal distances; said transposed feeder harness further coupling the remaining half of said dipoles to said feed terminals.
References Cited (Backward Citations)
US2977597A
Cited
US3110030A
Cited
US3210768A
Cited
US3271774A
Cited
US3440658A
Cited
US3509573A
Cited
US3427659A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |