US3754271A - Broadband antenna polarizer - Google Patents
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- US3754271A US3754271A US00268479A US3754271DA US3754271A US 3754271 A US3754271 A US 3754271A US 00268479 A US00268479 A US 00268479A US 3754271D A US3754271D A US 3754271DA US 3754271 A US3754271 A US 3754271A
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
- H01Q15/24—Polarising devices; Polarisation filters
- H01Q15/242—Polarisation converters
- H01Q15/244—Polarisation converters converting a linear polarised wave into a circular polarised wave
Definitions
- the meanderline axes in one set of alternate arrays are thus aligned in parallel planes 52 US.
- Cl 343/756, 343/786, 343/909 Spaced by meanderline 51 Int. (:1. H0lq 19/00 in 'emaming secmd alternate arrays are 58] Field of Search 343/756 786 909 also aligned in parallel planes spaced apart by one array-period; and the second set of parallel planes are off- 56] References Cited set or staggered by a distance equal to one-half of an array-period from the first set of parallel planes.
- a po- UNITED STATES PATENTS larizer comprising a plurality of such staggered arrays 3,560,984 2/1971 Lee et al 343/756 has utility when placed in front of the aperture of pyra- 3,089,142 5/1963 Wlckersham 343/756 mida] hom antenna f converting the linearly polarized wave of the horn to a circularly polarized wave.
- ABSTRACT In a meanderline array random-polarizer comprising a 4 Claims, 8 Drawing Figures PMENYEUMMI m3 SHEEI 2 BF 3 FIIL v NIL .IIIL
- FIG.7 (b) BROADBAND ANTENNA POLARIZER BACKGROUND OF THE INVENTION
- This invention relates to polarizers and more particularly to a broadband polarizer for use in converting a linearly polarized wave to one having circular polarization.
- a polarizer of the type to which this invention relates may, for example, be constructed as a radome or cover placed in front of the aperture of an antenna such as a pyramidal horn for the purpose of converting the linearly polarized wave in the horn to a circularly polarized wave on the other side of the polarizer.
- a polarizer consists of a plurality of arrays of metallic meanderline strips extending across the horn aperture at an angle of 45 to the plane of polarization of the horn.
- the effect is to change by substantially 90 the relative phase of the two orthogonally related componets of the linearly polarized signal of the horn antenna as both components propogate through the polarizer, thus achieving circular or near circular polarization on the side of the polarizer opposite from the antenna.
- the effectiveness and value of such a polarizer is often determined primarily by the frequency bandwidth over which the radiation pattern remains circularly or nearly circularly polarized, where the quality of the prevailing polarization relative to the ideal case (exact circular polarization) is described by the "axial ratio of the radiated field.
- An electric field axial ratio of unity or 0.0 db corresponds exactly to circular polarization.
- a typical limit for the axial ratio of satisfactory circularly polarized antenna systems is V? in field strength variation, or 3 db.
- a meanderline array radome-polarizer comprising a plurality of meanderline arrays stacked in the direction of the horn axis.
- Each array comprises a plurality of meanderline conductors preferably formed by photoetching a thin, copper-clad dielectric board.
- Each line has a rectangular serpentine shape resembling a square wave with the conductive strip formed symmetrically about the longitudinal axis of the line so as to appear to meander about that axis.
- the axes of the meanderlines of the several arrays in the polarizer are parallel and adjacent lines in each array have the same lateral spacing and are aligned with each other in the direction of propagation of the electromagnetic waves through the polarizer.
- the axes of all the lines in the several arrays lie in parallel planes which are perpendicular to the planes of the arrays.
- the axes of the meanderlines extend diagonally of the horn aperture at an angle of 45 degrees to the plane of polarization of the horn.
- meanderline array polarizer as compared to other prior art polarizers is that the former has no intrinsic or theoretical low-frequency operating limit.
- a low-frequency operating limit always prevails, being set primarily by the physical dimensions of the meanderlines, the arrayperiod and the total number of arrays employed. Decreasing such a low-frequency operating limit by any significant or useful amount cannot be achieved without employing a larger number of meanderline arrays of significantly different physical dimensions from those which set the original low-frequency operating limit above implied.
- An object of this invention is the provision of meanderline array radome-polan'zers which have no deterioration in low-frequency operating limits compared to the corresponding prior art polarizers but which are operative with substantial improvement or decrease in axial ratios to extended higher frequency limits.
- the upperfrequency operating limits of meanderline array radome-polarizers are significantly increased by staggering or laterally offsetting the meanderlines of adjacent arrays and such improvement is achieved with no deterioration or increase in low-frequency operating limits.
- FIG. I is a schematic elevational view of a prior art horn antenna and polarizer combination
- FIG. 2 is a front view of the polarizer taken on line 2-2 of FIG. 1;
- FIG. 3 is greatly enlarged fragmentary view of the po-Inventizer of FIG. 2 showing details of the meanderline array construction
- FIG. 4 is a section of the prior art polarizer taken on line 4-4 of FIG. 3;
- FIG. 5 is a fragmentary plan view similar to FIG. 3 showing a polarizer with the positions of lines in adjacent arrays staggered in accordance with the invention
- FIG. 6 is a transverse section taken on line 6-6 of FIG. 5;
- FIGS. 7(a) and 7(b) illustrate comparative performance curves of polarizers embodying the invention and those of the prior art for five-layer and six-layer polarizers.
- FIGS. 1 and 2 illustrate a pyramidal horn antenna 10 connected at one end to a waveguide 11 and at the other or aperture end to a polarizer 12.
- Horn 10 is linearly polarized in the direction of the electric vector shown by the arrow E
- the purpose of polarizer 12 is to convert the signal passing through it from linear to circular polarization by delaying one of the orthogonal components E of the vector E; by degrees with respect to the other orthogonal component E,..
- the aperture of born 10 is rectangular as shown and polarizer 12 comprises a plurality of meanderline arrays 14, see FIGS. 3 and 4, which extend transversely of the horn axis A.
- Each of the arrays 14 comprises a plurality of conductive meanderlines 15, described in detail below, formed on a thin, low-loss dielectric sheet 16 preferably by photoetching a conductive covering on the sheet, and the arrays are separated and supported by low-loss spacers 17 such as polyfoam or thinwalled dielectric honeycomb material.
- the lines in each array have parallel axes M and the arrays are stacked to maintain this parallel relationship throughout the polarizer. As shown in FIG.
- the polarizer is oriented with line axes M at an angle of 45 with respect to the polarization E of the horn.
- the meanderlines produce a phase differential for the components 15,. and E of the vector E such that the component E normal to the axes M is delayed with respect to the orthogonal component E
- Selection of the number of arrays for polarizer 12 is made to provide the desired 90 degree phase differential between the components E and E to produce circular polarization.
- Each meanderline 15 comprises a conductive strip which has a sepentine preferably rectangular shape and which extends longitudinally along and transversely of axis M in the manner of a square wave.
- Each meanderline is physically defined by its longitudinal period b, transverse length l, width w of the longitudinally extending legs, width s of the transversely extending legs, and the thickness t of the strip.
- the array is further defined by the distance a between axes of adjacent meanderlines, called the period of the array. The spacing between adjacent arrays is denoted as H.
- each meanderline, the array-period a and the interarray spacing H are selected in accordance with the number of arrays in the polarizer so as to provide the approximately 90 phase shift between orthogonal components needed to produce the nearly-circular polarization at all usable signal frequencies.
- FIG. 4 Another structural feature of prior art polarizers is the stacking of the substantially identical arrays 14 in such a manner that the meanderlines 15 on each array are aligned respectively with the meanderlines of all the other arrays. This is shown in FIG. 4 wherein the laterally spaced axes M of the meanderlines in the four arrays 14 are aligned so as to lie in planes P P and P which are parallel to each other and extend generally in the direction of propagation of the signal through the polarizer.
- meanderline array radome-polarizer relates to a prior art construction and does not per se constitute this invention.
- Polarizer l8 comrises a plurality of meanderline arrays 19a 19d, inclusive, substantially identical to the foregoing arrays 14 and stacked in such a manner that the axes M and M of meanderlines 15 and 15', respectively, in adjacent arrays are parallel to but offset from each other by a distance corresponding to one-half of the array-period a.
- the axes of the lines in alternate arrays of the polarizer are aligned with each other, i.e., lie in the same plane, but are offset from the planes containing the axes of the lines in the other arrays by a distance preferably equal to a/2 or one-half the period of the array.
- Planes P,, P and P containing the axes of the meanderlines 15 of arrays 19a and 190, see FIG. 6, are therefore displaced by 11/2 from planes P P and P respectively, containing the axes of the meanderlines 15 of arrays 19b and 19d.
- a pyramidal horn antenna with either of the polarizers placed on its aperture was employed as a receiving antenna with the peak of its radiation pattern pointing directly at a linearly polarized transmitting antenna.
- the radiation pattern of this latter antenna was boresighted precisely in the direction of the receiving antenna.
- the transmission line connected to the transmitting antenna contained a high-quality rotary joint which permitted continuous rotation of the transmitted radiation pattern about its boresight axes. Such rotation causes a variation in the received signal level as a function of time, the variation being identically equal to the axial ratio of the polarizer.
- the signal variation (or axial ratio) described above was recorded employing conventional received-signal-strength recording equipment.
- FIG. 7 shows a comparison of performance curves of the five-array polarizers and FIG. 7(b) shows similar curves for the six-array polarizer.
- the broken line curves show performance of the prior art polarizers of FIGS. 3 and 4, the solid line curves for the polarizers of FIGS. 5 and 6 embodying the invention.
- FIG. 7(a) shows a comparison of performance curves of the five-array polarizers
- FIG. 7(b) shows similar curves for the six-array polarizer.
- the broken line curves show performance of the prior art polarizers of FIGS. 3 and 4, the solid line curves for the polarizers of FIGS. 5 and 6 embodying the invention.
- FIG. 7(a) shows a comparison of performance curves of the five-array polarizers
- FIG. 7(b) shows similar curves for the six-array polarizer.
- the broken line curves show performance of the prior art polarizers of FIGS. 3
- FIG. 7(a) shows that five-array polarizer of the prior art operated satisfactorily over a frequency range of 6.9 to 14.7 GHz whereas the five-array polarizer embodying this invention with staggered arrays 0perated satisfactorily over the frequency range of 6.9 15.8 GHz, for a bandwidth increase of approximately 7.5 percent. It will be noted from FIG. 7(a) that the performance curves are substantially identical over most of the lower two-thirds of the frequency band and that the polarizer embodying the invention has a substantially improved axial ratio as well as an extended frequency range over the remaining upper portion of the band.
- the performance curve shown in FIG. 7(b) for the six-array polarizer indicates that the polarizer embodying this invention produced an increase in the operating bandwidth of 12.5 percent over the otherwise identical polarizer of the prior art.
- the performance curves of the polarizers embodying the invention and of the prior art were substantially the same over the lower 65 percent of the operating frequency range with the polarizer embodying the invention likewise having a substantially improved axial ratio over the prior art polarizer for the remaining upper portion of the band.
- a polarizer comprising a plurality of meanderline arrays arranged in stacked spaced relation with the planes of the arrays parallel,
- each array comprising a plurality of conductors formed in the configuration of meanderlines having parallel axes
- the axes of meanderlines of adjacent arrays being parallel to and offset from each other by a predetermined distance while axes of such lines in alternate arrays are aligned with each other.
- a pyramidal horn antenna and a meanderline array radome-polarizer said antenna having a longitudinal axis and an aperture and adapted to be linearly polarized, said polarizer being disposed in said horn aperture transversely of the horn axis and having a plurality of arrays of substantially identical conductive meanderlines stacked in the direction of said antenna axis, each array having a plurality of laterally spaced meanderlines with parallel axes extending at an angle of 45 to the plane of polarization of said horn, the improvement consisting of a polarizer in which adjacent meanderlines in adjacent arrays are laterally offset by a predetermined distance.
Abstract
In a meanderline array random-polarizer comprising a plurality of stacked substantially identical arrays of laterally spaced square-wave shaped conductive strips or meanderlines arranged with parallel extending axes with each such axis spaced one array-period from its nearest counterparts, the improvement consisting of offsetting or staggering the meanderline axes of adjacent arrays by a distance preferably equal to one-half of the array-period. The meanderline axes in one set of alternate arrays are thus aligned in parallel planes spaced apart by an arrayperiod; the meanderline axes in the remaining or second set of alternate arrays are also aligned in parallel planes spaced apart by one array-period; and the second set of parallel planes are offset or staggered by a distance equal to one-half of an arrayperiod from the first set of parallel planes. A polarizer comprising a plurality of such staggered arrays has utility when placed in front of the aperture of pyramidal horn antenna for converting the linearly polarized wave of the horn to a circularly polarized wave.
Description
JTD-IDOOR 8-2l-73 GR 3 7549271 llnited States Patent [1 1 [111 3,754,271
Epis Aug. 21, 1973 BROADBAND ANTENNA POLARIZER plurality of stacked substantially identical arrays of laterally spaced square-wave shaped conductive strips or [75] Inventor James Sunnyvale meanderlines arranged with parallel extending axes [73] ss gne G ylv ni In p with each such axis spaced one array-period from its Mountain View, Calif. nearest counterparts, the improvement consisting of offsetting orstaggering the meanderline axes of adja- [22] Flled' July 1972 cent arrays by a distance preferably equal to one-half [21] Appl. No.: 268,479 of the array-period. The meanderline axes in one set of alternate arrays are thus aligned in parallel planes 52 US. Cl 343/756, 343/786, 343/909 Spaced by meanderline 51 Int. (:1. H0lq 19/00 in 'emaming secmd alternate arrays are 58] Field of Search 343/756 786 909 also aligned in parallel planes spaced apart by one array-period; and the second set of parallel planes are off- 56] References Cited set or staggered by a distance equal to one-half of an array-period from the first set of parallel planes. A po- UNITED STATES PATENTS larizer comprising a plurality of such staggered arrays 3,560,984 2/1971 Lee et al 343/756 has utility when placed in front of the aperture of pyra- 3,089,142 5/1963 Wlckersham 343/756 mida] hom antenna f converting the linearly polarized wave of the horn to a circularly polarized wave. Primary Examiner-Eli Lieberman Attorney-Norman J. OMalley et al.
[57] ABSTRACT In a meanderline array random-polarizer comprising a 4 Claims, 8 Drawing Figures PMENYEUMMI m3 SHEEI 2 BF 3 FIIL v NIL .IIIL
AJ E
FIT!
FIG. 5
AXIAL RATIO (DB) PAIENIEnAuw ms 3754.271
A polarizer of the type to which this invention relates may, for example, be constructed as a radome or cover placed in front of the aperture of an antenna such as a pyramidal horn for the purpose of converting the linearly polarized wave in the horn to a circularly polarized wave on the other side of the polarizer. Such a polarizer consists of a plurality of arrays of metallic meanderline strips extending across the horn aperture at an angle of 45 to the plane of polarization of the horn. The effect is to change by substantially 90 the relative phase of the two orthogonally related componets of the linearly polarized signal of the horn antenna as both components propogate through the polarizer, thus achieving circular or near circular polarization on the side of the polarizer opposite from the antenna. The effectiveness and value of such a polarizer is often determined primarily by the frequency bandwidth over which the radiation pattern remains circularly or nearly circularly polarized, where the quality of the prevailing polarization relative to the ideal case (exact circular polarization) is described by the "axial ratio of the radiated field. An electric field axial ratio of unity or 0.0 db corresponds exactly to circular polarization. A typical limit for the axial ratio of satisfactory circularly polarized antenna systems is V? in field strength variation, or 3 db.
One prior art construction of a polarizer of this type is called a meanderline array radome-polarizer comprising a plurality of meanderline arrays stacked in the direction of the horn axis. Each array comprises a plurality of meanderline conductors preferably formed by photoetching a thin, copper-clad dielectric board. Each line has a rectangular serpentine shape resembling a square wave with the conductive strip formed symmetrically about the longitudinal axis of the line so as to appear to meander about that axis. The axes of the meanderlines of the several arrays in the polarizer are parallel and adjacent lines in each array have the same lateral spacing and are aligned with each other in the direction of propagation of the electromagnetic waves through the polarizer. In other words, the axes of all the lines in the several arrays lie in parallel planes which are perpendicular to the planes of the arrays. When mounted in the operative position on the horn antenna, the axes of the meanderlines extend diagonally of the horn aperture at an angle of 45 degrees to the plane of polarization of the horn.
An advantageous and inherent characteristic of the meanderline array polarizer as compared to other prior art polarizers is that the former has no intrinsic or theoretical low-frequency operating limit. In any particular practical polarizer, however, a low-frequency operating limit always prevails, being set primarily by the physical dimensions of the meanderlines, the arrayperiod and the total number of arrays employed. Decreasing such a low-frequency operating limit by any significant or useful amount cannot be achieved without employing a larger number of meanderline arrays of significantly different physical dimensions from those which set the original low-frequency operating limit above implied.
Attempts to extend the prevailing high-frequency operating limit already set as described above have not met with success. Antenna systems in which such polarizers are used are therefore bandwidth limited.
An object of this invention is the provision of meanderline array radome-polan'zers which have no deterioration in low-frequency operating limits compared to the corresponding prior art polarizers but which are operative with substantial improvement or decrease in axial ratios to extended higher frequency limits.
SUMMARY OF THE INVENTION In accordance with this invention, the upperfrequency operating limits of meanderline array radome-polarizers are significantly increased by staggering or laterally offsetting the meanderlines of adjacent arrays and such improvement is achieved with no deterioration or increase in low-frequency operating limits.
DESCRIPTION OF THE DRAWINGS FIG. I is a schematic elevational view of a prior art horn antenna and polarizer combination;
FIG. 2 is a front view of the polarizer taken on line 2-2 of FIG. 1;
FIG. 3 is greatly enlarged fragmentary view of the po- Iarizer of FIG. 2 showing details of the meanderline array construction;
FIG. 4 is a section of the prior art polarizer taken on line 4-4 of FIG. 3;
FIG. 5 is a fragmentary plan view similar to FIG. 3 showing a polarizer with the positions of lines in adjacent arrays staggered in accordance with the invention;
FIG. 6 is a transverse section taken on line 6-6 of FIG. 5; and
FIGS. 7(a) and 7(b) illustrate comparative performance curves of polarizers embodying the invention and those of the prior art for five-layer and six-layer polarizers.
DESCRIPTION OF PREFERRED EMBODIMENT Referring now to the drawings, FIGS. 1 and 2 illustrate a pyramidal horn antenna 10 connected at one end to a waveguide 11 and at the other or aperture end to a polarizer 12. Horn 10 is linearly polarized in the direction of the electric vector shown by the arrow E The purpose of polarizer 12 is to convert the signal passing through it from linear to circular polarization by delaying one of the orthogonal components E of the vector E; by degrees with respect to the other orthogonal component E,..
The aperture of born 10 is rectangular as shown and polarizer 12 comprises a plurality of meanderline arrays 14, see FIGS. 3 and 4, which extend transversely of the horn axis A. Each of the arrays 14 comprises a plurality of conductive meanderlines 15, described in detail below, formed on a thin, low-loss dielectric sheet 16 preferably by photoetching a conductive covering on the sheet, and the arrays are separated and supported by low-loss spacers 17 such as polyfoam or thinwalled dielectric honeycomb material. The lines in each array have parallel axes M and the arrays are stacked to maintain this parallel relationship throughout the polarizer. As shown in FIG. 2, the polarizer is oriented with line axes M at an angle of 45 with respect to the polarization E of the horn. As a consequence, the meanderlines produce a phase differential for the components 15,. and E of the vector E such that the component E normal to the axes M is delayed with respect to the orthogonal component E Selection of the number of arrays for polarizer 12 is made to provide the desired 90 degree phase differential between the components E and E to produce circular polarization.
Each meanderline 15 comprises a conductive strip which has a sepentine preferably rectangular shape and which extends longitudinally along and transversely of axis M in the manner of a square wave. Thus the conductor meanders from one side to the other of Axis M, which accounts for its name. Each meanderline is physically defined by its longitudinal period b, transverse length l, width w of the longitudinally extending legs, width s of the transversely extending legs, and the thickness t of the strip. The array is further defined by the distance a between axes of adjacent meanderlines, called the period of the array. The spacing between adjacent arrays is denoted as H. The dimensions of each meanderline, the array-period a and the interarray spacing H are selected in accordance with the number of arrays in the polarizer so as to provide the approximately 90 phase shift between orthogonal components needed to produce the nearly-circular polarization at all usable signal frequencies.
Another structural feature of prior art polarizers is the stacking of the substantially identical arrays 14 in such a manner that the meanderlines 15 on each array are aligned respectively with the meanderlines of all the other arrays. This is shown in FIG. 4 wherein the laterally spaced axes M of the meanderlines in the four arrays 14 are aligned so as to lie in planes P P and P which are parallel to each other and extend generally in the direction of propagation of the signal through the polarizer.
The foregoing description of the meanderline array radome-polarizer relates to a prior art construction and does not per se constitute this invention.
In accordance with this invention, a substantial improvement in the operating bandwidth of the meanderline array radome-polarizer is achieved with polarizer 18, see FIGS. 5 and 6. Polarizer l8 comrises a plurality of meanderline arrays 19a 19d, inclusive, substantially identical to the foregoing arrays 14 and stacked in such a manner that the axes M and M of meanderlines 15 and 15', respectively, in adjacent arrays are parallel to but offset from each other by a distance corresponding to one-half of the array-period a. Thus the axes of the lines in alternate arrays of the polarizer are aligned with each other, i.e., lie in the same plane, but are offset from the planes containing the axes of the lines in the other arrays by a distance preferably equal to a/2 or one-half the period of the array. Planes P,, P and P containing the axes of the meanderlines 15 of arrays 19a and 190, see FIG. 6, are therefore displaced by 11/2 from planes P P and P respectively, containing the axes of the meanderlines 15 of arrays 19b and 19d.
Polarizers embodying this invention were constructed, tested and compared with otherwise identical prior art polarizers shown in FIGS. 3 and 4 for each of a five-array and a six-array polarizer. These polarizers had an inter-array spacer thickness H equal to 0.220 inch and 0.180 inch for the five-array and six-array units, respectively, and the conductors were of thickness t=0.00l5 inch and were photo-etched on 0.003 inch thick teflon-fiberglass dielectric sheet.
These polarizers were then tested in the following manner:
a. A pyramidal horn antenna with either of the polarizers placed on its aperture was employed as a receiving antenna with the peak of its radiation pattern pointing directly at a linearly polarized transmitting antenna. The radiation pattern of this latter antenna was boresighted precisely in the direction of the receiving antenna.
b. The transmission line connected to the transmitting antenna contained a high-quality rotary joint which permitted continuous rotation of the transmitted radiation pattern about its boresight axes. Such rotation causes a variation in the received signal level as a function of time, the variation being identically equal to the axial ratio of the polarizer. The signal variation (or axial ratio) described above was recorded employing conventional received-signal-strength recording equipment.
Results of these tests are shown in FIG. 7 wherein FIG. 7(a) shows a comparison of performance curves of the five-array polarizers and FIG. 7(b) shows similar curves for the six-array polarizer. The broken line curves show performance of the prior art polarizers of FIGS. 3 and 4, the solid line curves for the polarizers of FIGS. 5 and 6 embodying the invention. Using an axial ratio of 3 db as the tolerable limit for acceptable performance, FIG. 7(a) shows that five-array polarizer of the prior art operated satisfactorily over a frequency range of 6.9 to 14.7 GHz whereas the five-array polarizer embodying this invention with staggered arrays 0perated satisfactorily over the frequency range of 6.9 15.8 GHz, for a bandwidth increase of approximately 7.5 percent. It will be noted from FIG. 7(a) that the performance curves are substantially identical over most of the lower two-thirds of the frequency band and that the polarizer embodying the invention has a substantially improved axial ratio as well as an extended frequency range over the remaining upper portion of the band.
The performance curve shown in FIG. 7(b) for the six-array polarizer indicates that the polarizer embodying this invention produced an increase in the operating bandwidth of 12.5 percent over the otherwise identical polarizer of the prior art. As in the case of the fivearray polarizer, the performance curves of the polarizers embodying the invention and of the prior art were substantially the same over the lower 65 percent of the operating frequency range with the polarizer embodying the invention likewise having a substantially improved axial ratio over the prior art polarizer for the remaining upper portion of the band.
It is believed that the axial ratio performance improvement provided by polarizers embodying this invention as demonstrated by the performance curves of FIG. 7 is due to a significant reduction in certain deleterious or highly unfavorable effects of higher-order mode coupling between various arrays in the meanderline array radome-polarizer.
What is claimed is:
1. A polarizer comprising a plurality of meanderline arrays arranged in stacked spaced relation with the planes of the arrays parallel,
each array comprising a plurality of conductors formed in the configuration of meanderlines having parallel axes,
the axes of meanderlines of adjacent arrays being parallel to and offset from each other by a predetermined distance while axes of such lines in alternate arrays are aligned with each other.
2. The polarizer according to claim 1 wherein said predetermined distance is substantially equal to onehalf the distance between axes of adjacent lines in each array.
3. In the combination of a pyramidal horn antenna and a meanderline array radome-polarizer, said antenna having a longitudinal axis and an aperture and adapted to be linearly polarized, said polarizer being disposed in said horn aperture transversely of the horn axis and having a plurality of arrays of substantially identical conductive meanderlines stacked in the direction of said antenna axis, each array having a plurality of laterally spaced meanderlines with parallel axes extending at an angle of 45 to the plane of polarization of said horn, the improvement consisting of a polarizer in which adjacent meanderlines in adjacent arrays are laterally offset by a predetermined distance.
4. The combination according to claim 3 in which said distance is substantially the same as one-half the spacing between the axes of adjacnt lines in the same array.
Claims (4)
1. A polarizer comprising a plurality of meanderline arrays arranged in stacked spaced relation with the planes of the arrays parallel, each array comprising a plurality of conductors formed in the configuration of meanderlines having parallel axes, the axes of meanderlines of adjacent arrays being parallel to and offset from each other by a predetermined distance while axes of such lines in alternate arrays are aligned with each other.
2. The polarizer according to claim 1 wherein said predetermined distance is substantially equal to one-half the distance between axes of adjacent lines in each array.
3. In the combination of a pyramidal horn antenna and a meanderline array radome-polarizer, said antenna having a longitudinal axis and an aperture and adapted to be linearly polarized, said polarizer being disposed in said horn aperture transversely of the horn axis and having a pluralitY of arrays of substantially identical conductive meanderlines stacked in the direction of said antenna axis, each array having a plurality of laterally spaced meanderlines with parallel axes extending at an angle of 45* to the plane of polarization of said horn, the improvement consisting of a polarizer in which adjacent meanderlines in adjacent arrays are laterally offset by a predetermined distance.
4. The combination according to claim 3 in which said distance is substantially the same as one-half the spacing between the axes of adjacnt lines in the same array.
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US26847972A | 1972-07-03 | 1972-07-03 |
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US00268479A Expired - Lifetime US3754271A (en) | 1972-07-03 | 1972-07-03 | Broadband antenna polarizer |
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Cited By (56)
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US3854140A (en) * | 1973-07-25 | 1974-12-10 | Itt | Circularly polarized phased antenna array |
US3886558A (en) * | 1972-08-04 | 1975-05-27 | Secr Defence Brit | Artificial dielectric material for controlling antennae patterns |
US4125841A (en) * | 1977-05-17 | 1978-11-14 | Ohio State University Research Foundation | Space filter |
DE2821781A1 (en) * | 1977-05-31 | 1978-12-14 | Raytheon Co | HIGH FREQUENCY ANTENNA |
US4219820A (en) * | 1978-12-26 | 1980-08-26 | Hughes Aircraft Company | Coupling compensation device for circularly polarized horn antenna array |
US4228437A (en) * | 1979-06-26 | 1980-10-14 | The United States Of America As Represented By The Secretary Of The Navy | Wideband polarization-transforming electromagnetic mirror |
EP0042611A1 (en) * | 1980-06-24 | 1981-12-30 | Siemens Aktiengesellschaft | Conductive screen for circularly polarising electromagnetic waves |
EP0042612A1 (en) * | 1980-06-24 | 1981-12-30 | Siemens Aktiengesellschaft | Arrangement for transforming the polarization of electromagnetic waves |
EP0044502A1 (en) * | 1980-07-17 | 1982-01-27 | Siemens Aktiengesellschaft | Polarising device for conversion of linearly polarised into circularly polarised electromagnetic waves, mounted in front of a parabolic reflector antenna |
EP0044503A1 (en) * | 1980-07-17 | 1982-01-27 | Siemens Aktiengesellschaft | Polariser for the generation of circularly polarised electromagnetic waves |
EP0061831A1 (en) * | 1981-03-04 | 1982-10-06 | The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and | Improvements in or relating to stripline antennas |
EP0099318A1 (en) * | 1982-07-15 | 1984-01-25 | Elta Electronics Industries Ltd. | Reflecting plate antenna including a polarizer reflector |
US4568943A (en) * | 1983-05-31 | 1986-02-04 | Rca Corporation | Antenna feed with mode conversion and polarization conversion means |
US4652886A (en) * | 1986-03-17 | 1987-03-24 | Gte Government Systems Corporation | Multilayer antenna aperture polarizer |
FR2592993A1 (en) * | 1986-01-14 | 1987-07-17 | Singer Co | DOPPLER ANTENNA HAVING SLIT WAVES, CIRCULARLY POLARIZED AND METHOD FOR MANUFACTURING SUCH ANTENNA. |
US4786914A (en) * | 1985-01-25 | 1988-11-22 | E-Systems, Inc. | Meanderline polarization twister |
EP0468620A2 (en) * | 1990-07-26 | 1992-01-29 | Space Systems / Loral, Inc. | Dual band frequency reuse antenna |
US5258768A (en) * | 1990-07-26 | 1993-11-02 | Space Systems/Loral, Inc. | Dual band frequency reuse antenna |
US5337058A (en) * | 1993-04-16 | 1994-08-09 | United Technologies Corporation | Fast switching polarization diverse radar antenna system |
US5385623A (en) * | 1992-05-29 | 1995-01-31 | Hexcel Corporation | Method for making a material with artificial dielectric constant |
US5434587A (en) * | 1993-09-10 | 1995-07-18 | Hazeltine Corporation | Wide-angle polarizers with refractively reduced internal transmission angles |
US5502453A (en) * | 1991-12-13 | 1996-03-26 | Matsushita Electric Works, Ltd. | Planar antenna having polarizer for converting linear polarized waves into circular polarized waves |
US5563616A (en) * | 1994-03-18 | 1996-10-08 | California Microwave | Antenna design using a high index, low loss material |
US5754143A (en) * | 1996-10-29 | 1998-05-19 | Southwest Research Institute | Switch-tuned meandered-slot antenna |
US6359599B2 (en) | 2000-05-31 | 2002-03-19 | Bae Systems Information And Electronic Systems Integration Inc | Scanning, circularly polarized varied impedance transmission line antenna |
US6373440B2 (en) | 2000-05-31 | 2002-04-16 | Bae Systems Information And Electronic Systems Integration, Inc. | Multi-layer, wideband meander line loaded antenna |
US6452549B1 (en) | 2000-05-02 | 2002-09-17 | Bae Systems Information And Electronic Systems Integration Inc | Stacked, multi-band look-through antenna |
WO2002084801A1 (en) * | 2001-04-13 | 2002-10-24 | Comsat Corporation | Dual circular polarization flat plate antenna that uses multilayer structure with meander line polarizer |
US6480158B2 (en) | 2000-05-31 | 2002-11-12 | Bae Systems Information And Electronic Systems Integration Inc. | Narrow-band, crossed-element, offset-tuned dual band, dual mode meander line loaded antenna |
US6486850B2 (en) | 2000-04-27 | 2002-11-26 | Bae Systems Information And Electronic Systems Integration Inc. | Single feed, multi-element antenna |
US20030020658A1 (en) * | 2000-04-27 | 2003-01-30 | Apostolos John T. | Activation layer controlled variable impedance transmission line |
WO2003098323A1 (en) * | 2002-05-17 | 2003-11-27 | Qinetiq Limited | Apparatus for redirecting radiation |
US20030227417A1 (en) * | 2002-01-17 | 2003-12-11 | English Errol K. | Electromagnetic-field polarization twister |
US20050007289A1 (en) * | 2003-07-07 | 2005-01-13 | Zarro Michael S. | Multi-band horn antenna using frequency selective surfaces |
US6879298B1 (en) * | 2003-10-15 | 2005-04-12 | Harris Corporation | Multi-band horn antenna using corrugations having frequency selective surfaces |
US20050104791A1 (en) * | 2001-04-13 | 2005-05-19 | Sun Liang Q. | Two-layer wide-band meander-line polarizer |
US20070046525A1 (en) * | 2005-02-15 | 2007-03-01 | Holbrook David S | Electromagnetic scanning imager |
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KR100905914B1 (en) * | 2007-09-03 | 2009-07-02 | 주식회사 아이두잇 | Dual linear polarization horn array type antenna |
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US20100232017A1 (en) * | 2008-06-19 | 2010-09-16 | Ravenbrick Llc | Optical metapolarizer device |
US20110074427A1 (en) * | 2009-09-28 | 2011-03-31 | Smith International, Inc. | Directional Resistivity Antenna Shield |
US20130249755A1 (en) * | 2010-12-22 | 2013-09-26 | Cobham Cts Ltd | Electromagnetic wave polarizer screen |
US8947760B2 (en) | 2009-04-23 | 2015-02-03 | Ravenbrick Llc | Thermotropic optical shutter incorporating coatable polarizers |
US9356353B1 (en) | 2012-05-21 | 2016-05-31 | The Boeing Company | Cog ring antenna for phased array applications |
EP3076482A1 (en) * | 2015-04-02 | 2016-10-05 | Progress Rail Inspection & Information Systems S.r.l. | Radar obstacle detector for a railway crossing |
US20170288291A1 (en) * | 2015-06-03 | 2017-10-05 | Mitsubishi Electric Corporation | Horn antenna |
US9912050B2 (en) | 2015-08-14 | 2018-03-06 | The Boeing Company | Ring antenna array element with mode suppression structure |
US10230150B2 (en) * | 2011-12-06 | 2019-03-12 | Viasat, Inc. | Dual-circular polarized antenna system |
US10243245B2 (en) | 2015-05-27 | 2019-03-26 | Viasat, Inc. | Partial dielectric loaded septum polarizer |
CN109524794A (en) * | 2018-11-28 | 2019-03-26 | 四川九洲电器集团有限责任公司 | A kind of shaped form circular polarizer |
US10249922B2 (en) | 2015-05-27 | 2019-04-02 | Viasat, Inc. | Partial dielectric loaded septum polarizer |
US10547117B1 (en) | 2017-12-05 | 2020-01-28 | Unites States Of America As Represented By The Secretary Of The Air Force | Millimeter wave, wideband, wide scan phased array architecture for radiating circular polarization at high power levels |
US10840573B2 (en) | 2017-12-05 | 2020-11-17 | The United States Of America, As Represented By The Secretary Of The Air Force | Linear-to-circular polarizers using cascaded sheet impedances and cascaded waveplates |
US11831073B2 (en) | 2020-07-17 | 2023-11-28 | Synergy Microwave Corporation | Broadband metamaterial enabled electromagnetic absorbers and polarization converters |
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US3886558A (en) * | 1972-08-04 | 1975-05-27 | Secr Defence Brit | Artificial dielectric material for controlling antennae patterns |
US3854140A (en) * | 1973-07-25 | 1974-12-10 | Itt | Circularly polarized phased antenna array |
US4125841A (en) * | 1977-05-17 | 1978-11-14 | Ohio State University Research Foundation | Space filter |
DE2821781A1 (en) * | 1977-05-31 | 1978-12-14 | Raytheon Co | HIGH FREQUENCY ANTENNA |
US4219820A (en) * | 1978-12-26 | 1980-08-26 | Hughes Aircraft Company | Coupling compensation device for circularly polarized horn antenna array |
US4228437A (en) * | 1979-06-26 | 1980-10-14 | The United States Of America As Represented By The Secretary Of The Navy | Wideband polarization-transforming electromagnetic mirror |
US4387377A (en) * | 1980-06-24 | 1983-06-07 | Siemens Aktiengesellschaft | Apparatus for converting the polarization of electromagnetic waves |
EP0042611A1 (en) * | 1980-06-24 | 1981-12-30 | Siemens Aktiengesellschaft | Conductive screen for circularly polarising electromagnetic waves |
EP0042612A1 (en) * | 1980-06-24 | 1981-12-30 | Siemens Aktiengesellschaft | Arrangement for transforming the polarization of electromagnetic waves |
DE3023561A1 (en) * | 1980-06-24 | 1982-01-14 | Siemens AG, 1000 Berlin und 8000 München | POLARIZATION CONVERTER FOR ELECTROMAGNETIC WAVES |
DE3023562A1 (en) * | 1980-06-24 | 1982-01-14 | Siemens AG, 1000 Berlin und 8000 München | DEVICE FOR POLARIZATION CONVERSION OF ELECTROMAGNETIC WAVES |
EP0044502A1 (en) * | 1980-07-17 | 1982-01-27 | Siemens Aktiengesellschaft | Polarising device for conversion of linearly polarised into circularly polarised electromagnetic waves, mounted in front of a parabolic reflector antenna |
DE3027093A1 (en) * | 1980-07-17 | 1982-02-11 | Siemens AG, 1000 Berlin und 8000 München | RE-POLARIZING DEVICE FOR GENERATING CIRCULAR POLARIZED ELECTROMAGNETIC WAVES |
EP0044503A1 (en) * | 1980-07-17 | 1982-01-27 | Siemens Aktiengesellschaft | Polariser for the generation of circularly polarised electromagnetic waves |
US4477815A (en) * | 1980-07-17 | 1984-10-16 | Siemens Aktiengesellschaft | Radome for generating circular polarized electromagnetic waves |
US4479128A (en) * | 1980-07-17 | 1984-10-23 | Siemens Aktiengesellschaft | Polarization means for generating circularly polarized electro-magnetic waves |
EP0061831A1 (en) * | 1981-03-04 | 1982-10-06 | The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and | Improvements in or relating to stripline antennas |
EP0099318A1 (en) * | 1982-07-15 | 1984-01-25 | Elta Electronics Industries Ltd. | Reflecting plate antenna including a polarizer reflector |
US4599623A (en) * | 1982-07-15 | 1986-07-08 | Michael Havkin | Polarizer reflector and reflecting plate scanning antenna including same |
US4568943A (en) * | 1983-05-31 | 1986-02-04 | Rca Corporation | Antenna feed with mode conversion and polarization conversion means |
US4786914A (en) * | 1985-01-25 | 1988-11-22 | E-Systems, Inc. | Meanderline polarization twister |
FR2592993A1 (en) * | 1986-01-14 | 1987-07-17 | Singer Co | DOPPLER ANTENNA HAVING SLIT WAVES, CIRCULARLY POLARIZED AND METHOD FOR MANUFACTURING SUCH ANTENNA. |
US4652886A (en) * | 1986-03-17 | 1987-03-24 | Gte Government Systems Corporation | Multilayer antenna aperture polarizer |
EP0468620A3 (en) * | 1990-07-26 | 1992-05-20 | Space Systems / Loral Inc. | Dual band frequency reuse antenna |
US5258768A (en) * | 1990-07-26 | 1993-11-02 | Space Systems/Loral, Inc. | Dual band frequency reuse antenna |
EP0468620A2 (en) * | 1990-07-26 | 1992-01-29 | Space Systems / Loral, Inc. | Dual band frequency reuse antenna |
US5502453A (en) * | 1991-12-13 | 1996-03-26 | Matsushita Electric Works, Ltd. | Planar antenna having polarizer for converting linear polarized waves into circular polarized waves |
US5385623A (en) * | 1992-05-29 | 1995-01-31 | Hexcel Corporation | Method for making a material with artificial dielectric constant |
US5337058A (en) * | 1993-04-16 | 1994-08-09 | United Technologies Corporation | Fast switching polarization diverse radar antenna system |
US5434587A (en) * | 1993-09-10 | 1995-07-18 | Hazeltine Corporation | Wide-angle polarizers with refractively reduced internal transmission angles |
USRE36506E (en) * | 1994-03-18 | 2000-01-18 | California Microwave | Antenna design using a high index, low loss material |
US5563616A (en) * | 1994-03-18 | 1996-10-08 | California Microwave | Antenna design using a high index, low loss material |
US5754143A (en) * | 1996-10-29 | 1998-05-19 | Southwest Research Institute | Switch-tuned meandered-slot antenna |
US6486850B2 (en) | 2000-04-27 | 2002-11-26 | Bae Systems Information And Electronic Systems Integration Inc. | Single feed, multi-element antenna |
US20030020658A1 (en) * | 2000-04-27 | 2003-01-30 | Apostolos John T. | Activation layer controlled variable impedance transmission line |
US6774745B2 (en) | 2000-04-27 | 2004-08-10 | Bae Systems Information And Electronic Systems Integration Inc | Activation layer controlled variable impedance transmission line |
US6452549B1 (en) | 2000-05-02 | 2002-09-17 | Bae Systems Information And Electronic Systems Integration Inc | Stacked, multi-band look-through antenna |
US6359599B2 (en) | 2000-05-31 | 2002-03-19 | Bae Systems Information And Electronic Systems Integration Inc | Scanning, circularly polarized varied impedance transmission line antenna |
US6373440B2 (en) | 2000-05-31 | 2002-04-16 | Bae Systems Information And Electronic Systems Integration, Inc. | Multi-layer, wideband meander line loaded antenna |
US6480158B2 (en) | 2000-05-31 | 2002-11-12 | Bae Systems Information And Electronic Systems Integration Inc. | Narrow-band, crossed-element, offset-tuned dual band, dual mode meander line loaded antenna |
WO2002084801A1 (en) * | 2001-04-13 | 2002-10-24 | Comsat Corporation | Dual circular polarization flat plate antenna that uses multilayer structure with meander line polarizer |
US20050104791A1 (en) * | 2001-04-13 | 2005-05-19 | Sun Liang Q. | Two-layer wide-band meander-line polarizer |
US20030227417A1 (en) * | 2002-01-17 | 2003-12-11 | English Errol K. | Electromagnetic-field polarization twister |
US6906685B2 (en) | 2002-01-17 | 2005-06-14 | Mission Research Corporation | Electromagnetic-field polarization twister |
WO2003098323A1 (en) * | 2002-05-17 | 2003-11-27 | Qinetiq Limited | Apparatus for redirecting radiation |
US20050168388A1 (en) * | 2002-05-17 | 2005-08-04 | Qinetiq Limited | Apparatus for redirecting radiation |
US7176827B2 (en) | 2002-05-17 | 2007-02-13 | Qinetiq Limited | Apparatus for redirecting radiation |
US20050007289A1 (en) * | 2003-07-07 | 2005-01-13 | Zarro Michael S. | Multi-band horn antenna using frequency selective surfaces |
US6985118B2 (en) * | 2003-07-07 | 2006-01-10 | Harris Corporation | Multi-band horn antenna using frequency selective surfaces |
US6879298B1 (en) * | 2003-10-15 | 2005-04-12 | Harris Corporation | Multi-band horn antenna using corrugations having frequency selective surfaces |
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US20070046525A1 (en) * | 2005-02-15 | 2007-03-01 | Holbrook David S | Electromagnetic scanning imager |
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US8593157B2 (en) | 2005-02-15 | 2013-11-26 | Walleye Technologies, Inc. | Electromagnetic scanning imager |
US8253619B2 (en) | 2005-02-15 | 2012-08-28 | Techtronic Power Tools Technology Limited | Electromagnetic scanning imager |
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US9116302B2 (en) * | 2008-06-19 | 2015-08-25 | Ravenbrick Llc | Optical metapolarizer device |
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US8947760B2 (en) | 2009-04-23 | 2015-02-03 | Ravenbrick Llc | Thermotropic optical shutter incorporating coatable polarizers |
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US20130249755A1 (en) * | 2010-12-22 | 2013-09-26 | Cobham Cts Ltd | Electromagnetic wave polarizer screen |
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US20170288291A1 (en) * | 2015-06-03 | 2017-10-05 | Mitsubishi Electric Corporation | Horn antenna |
US9912050B2 (en) | 2015-08-14 | 2018-03-06 | The Boeing Company | Ring antenna array element with mode suppression structure |
US10840573B2 (en) | 2017-12-05 | 2020-11-17 | The United States Of America, As Represented By The Secretary Of The Air Force | Linear-to-circular polarizers using cascaded sheet impedances and cascaded waveplates |
US10547117B1 (en) | 2017-12-05 | 2020-01-28 | Unites States Of America As Represented By The Secretary Of The Air Force | Millimeter wave, wideband, wide scan phased array architecture for radiating circular polarization at high power levels |
US11211675B2 (en) | 2017-12-05 | 2021-12-28 | Government Of The United States, As Represented By The Secretary Of The Air Force | Linear-to-circular polarizer antenna |
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US11831073B2 (en) | 2020-07-17 | 2023-11-28 | Synergy Microwave Corporation | Broadband metamaterial enabled electromagnetic absorbers and polarization converters |
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