US4786914A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Meanderline polarization twister
Assignee: Raytheon Co
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Filing: 1985-01-25
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Granted: 1988-11-22
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Expires: 2005-01-25
Abstract
Abstract A polarization twister for twisting the polarization of a wide angle incident electromagnetic wave is described. Specifically, the polarization twister includes a reflector for reflecting the wide angle incident electromagnetic wave, a dielectric substrate having a longitudinal axis, a spacer bonded on a first side thereof to the dielectric substrate and on a second side thereof to the reflector, and an array of meanderline conductive strips etched on the dielectric substrate. Each meanderline conductive strip has an axis extending at a 45° angle with respect to the longitudinal axis of the dielectric substrate. In operation, the meanderline conductive strips serve to advance the phase of a parallel component of an incident E-field vector, and delay the phase of the perpendicular component thereof. Accordingly, the reflected field has its polarization twisted 90° from the incident polarization.
Inventors
- 👤 Te-Kao Wu
- 👤 Darrell L. Helms
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:24
CPC Classifications
H; H01; H01Q; H01Q15/00; H01Q15/24; H01Q15/242; H01Q15/246; H01Q15/248
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
172 words
A wide angle polarization twister fo twisting the polarization of an incident electromagnetic wave of wavelength λ, comprising: a dielectric substrate having a longitudinal axis and a dimension in thickness equal to 0.017λ; a spacer having first and second sides and a dimension "x" given by the expression x=0.275 λ, said dielectric substrate bonded to the first side of the spacer; a single layer of a plurality of meanderline conductive strips etched on said dielectric substrate, each meanderline conductive strip having a width "d"=0.31 λ and an axis extending at a 45° angle with respect to the longitudial axis of said dielectric substrate; a reflector bonded to the second side of the spacer for reflecting the wide angle incident electromagnetic wave with its polarization twisted 90°; and wherein each of the meanderline conductive strips has a longitudinal period "a", a distance "b", a transverse length "h", and a width "w" determined by the wavelength λ to provide the 90° twist of the electromagnetic wave by the single layer of meanderline conductive strips.
Claim 2
Dependent Claim
172 words
A wide angle polarization twister fo twisting the polarization of an incident electromagnetic wave of wavelength λ, comprising: a dielectric substrate having a longitudinal axis and a dimension in thickness equal to 0.017λ; a spacer having first and second sides and a dimension "x" given by the expression x=0.275 λ, said dielectric substrate bonded to the first side of the spacer; a single layer of a plurality of meanderline conductive strips etched on said dielectric substrate, each meanderline conductive strip having a width "d"=0.31 λ and an axis extending at a 45° angle with respect to the longitudial axis of said dielectric substrate; a reflector bonded to the second side of the spacer for reflecting the wide angle incident electromagnetic wave with its polarization twisted 90°; and wherein each of the meanderline conductive strips has a longitudinal period "a", a distance "b", a transverse length "h", and a width "w" determined by the wavelength λ to provide the 90° twist of the electromagnetic wave by the single layer of meanderline conductive strips.
Claim 3
Dependent Claim
47 words
The polarization twister as described in claim 1 wherein said incident electromagnetic wave includes an electric field vector having parallel and perpendicular components, said meanderline conductive strips including means for advancing a phase of said parallel component and means for delaying the phase of said perpendiclar component.
Claim 4
Dependent Claim
41 words
The polarization twister as described in claim 2 wherein when said incident electromagnetic wave is reflected off said reflector, said parallel and perpendicular components of said electric field vector are 180° out of phase, thereby resulting in said 90° polarization twist.
Claim 5
Dependent Claim
19 words
The polarization twister as described in claim 1 wherein said dielectric substrate is formed from a low-loss polytetrafluoroethylene/fiberglass material.
Claim 6
Dependent Claim
17 words
The polarization twister as described in claim 4 wherein the polytetrafluoroethylene/fiberglass dielectric substrate has a thickness approximately=0.017λ.
Claim 7
Dependent Claim
18 words
The polarization twister as described in claim 1 wherein said spacer is formed of a low-loss foam material.
Claim 8
Dependent Claim
16 words
The polarization twister as described in claim 6 wherein said foam spacer has a thickness approximately=0.275λ.
Claim 9
Dependent Claim
15 words
The polarization twister as described in claim 1 wherein said reflector is formed of aluminum.
Claim 10
Dependent Claim
28 words
The polarization twister as described in claim 1 wherein each of said meanderline conductive strips is a copper strip etched by printed circuit techniques on said dielectric substrate.
Claim 11
Dependent Claim
20 words
The polarization twister as described in claim 1 wherein each of said meanderline conductive strips has a longitudinal period approximately=0.1356λ.
Claim 12
Dependent Claim
27 words
The polarization twister as described in claim 1 wherein said meanderline conductive strips are formed on said dielectric substrate at a distance approximately=0.144λ apart from each other.
Claim 13
Dependent Claim
20 words
The polarization twister as described in claim 1 wherein each of said meanderline conductive strips has a transverse length approximately=0.0847λ.
Claim 14
Dependent Claim
19 words
The polarization twister as described in claim 1 where each of said meanderline conductive strips has a width approximately=0.0127λ.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-22 | 1992-05-23 | 1992-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-22 | 1996-05-23 | 1996-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-22 | 2000-05-23 | 2000-11-22 | $7700.00 | Window Closed / Lapsed |