US4220957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual frequency horn antenna system
Assignee: General Dynamics OTS Inc
•
Filing: 1979-06-01
•
Granted: 1980-09-02
•
Expires: 1999-06-01
Abstract
Abstract A feature of this invention is the provision of an antenna system providing two, coaxial, copolarized, independently focused beams: a relatively wide, low frequency, searching beam, and a relatively narrow, high frequency, tracking beam; and comprising a dual frequency, dual polarization feedhorn; a polarization dependent subreflector; a concave polarization reversing reflector; a concave polarization twisting reflector; and a planar frequency dependent dielectric lens.
Inventors
- 👤 Pope P. Britt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:32
CPC Classifications
H; H01; H01Q; H01Q25/00; H01Q25/002; H01Q19/00; H01Q19/06; H01Q19/062; H01Q19/065; H01Q19/10; H01Q19/18; H01Q19/19; H01Q19/195; H01Q5/00; H01Q5/40; H01Q5/45
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
110 words
An antenna system comprising: a feedhorn system providing a first, relatively low frequency wavefront of energy which is polarized in a first direction, and a second, relatively high frequency wavefront of energy which is polarized in a second direction at 90° to said first direction; a polarization dependent subreflector for said first frequency spaced forward of said feedhorn system; a concave polarization twisting reflector for said first frequency spaced aft of said polarization dependent subreflector; a concave polarization reversing reflector spaced aft of said concave polarization twisting reflector by 1/4 wavelength of said first frequency; and a dielectric lens for said second frequency spaced forward of said polarization dependent subreflector.
Claim 2
Dependent Claim
110 words
An antenna system comprising: a feedhorn system providing a first, relatively low frequency wavefront of energy which is polarized in a first direction, and a second, relatively high frequency wavefront of energy which is polarized in a second direction at 90° to said first direction; a polarization dependent subreflector for said first frequency spaced forward of said feedhorn system; a concave polarization twisting reflector for said first frequency spaced aft of said polarization dependent subreflector; a concave polarization reversing reflector spaced aft of said concave polarization twisting reflector by 1/4 wavelength of said first frequency; and a dielectric lens for said second frequency spaced forward of said polarization dependent subreflector.
Claim 3
Dependent Claim
26 words
A system according to claim 1 wherein: said dielectric lens serves as a radome to said first frequency and as a collimator to said second frequency.
Claim 4
Dependent Claim
13 words
A system according to claim 2 wherein: said lens is a Fresnel lens.
Claim 5
Dependent Claim
14 words
A system according to claim 2 wherein: said lens is a flat stepped plate.
Claim 6
Dependent Claim
23 words
A system according to claim 1 wherein: said polarization dependent subreflector passes said second frequency to said lens and reflects said first frequency.
Claim 7
Dependent Claim
68 words
A system according to claim 5 wherein: said first frequency as reflected by said subreflector is again reflected in part at 90° by said concave polarization twisting reflector, and again reflected in remaining part at 180° by said concave polarization reversing reflector, whereby said total first frequency wavefront is again reflected with a 90° phase shift relative to said first frequency wavefront as provided by said feedhorn system.
Claim 8
Dependent Claim
45 words
A system according to claim 6 wherein: said polarization dependent subreflector includes a grid of parallel conductors having a first orientation, and said concave polarization twisting reflector includes a grid of parallel conductors having a second orientation which is at 45° to said first orientation.
Claim 9
Dependent Claim
26 words
A system according to claim 1 wherein: said first and second wavefronts of energy, as transmitted by said antenna system, are coaxial and colinear in polarization.
References Cited (Backward Citations)
CA777935A
Cited
US2736895A
Cited
US2943324A
Cited
US3281850A
Cited
US3394378A
Cited
US3514779A
Cited
GB1512718A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-02 | 1984-03-03 | 1984-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-02 | 1988-03-03 | 1988-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-02 | 1992-03-03 | 1992-09-02 | $7700.00 | Window Closed / Lapsed |