Patent US2514682A successfully refreshed from Google Patents.
Patent US3775771A successfully refreshed from Google Patents.
US3775771A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flush mounted backfire circularly polarized antenna
Assignee: Singer Co
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Filing: 1972-04-27
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Granted: 1973-11-27
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Expires: 1992-04-27
Abstract
Abstract A flush mounted backfire antenna and array receptive to circularly polarized radiation and particularly adapted for aircraft application. Two orthogonally phased elements such as half-wave slots are arranged so that the projected angle of the E field of the elements is 90* in a backfire direction.
Inventors
- 👤 J Scherer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:01
CPC Classifications
H; H01; H01Q; H01Q21/00; H01Q21/0006; H01Q21/0037; H01Q21/0043; H01Q21/24
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
82 words
An antenna structure comprising electrically conducting means defining a ground plane having a center line longitudinally thereof, said means having a pair of crossed slot radiators therein with the center lines of said slots crossing each other at said center line and symmetrically disposed with an angle greater than 90* therebetween at said center line, and means electrically energizing said slots ninety degrees out-ofphase to thus radiate from the slots circularly polarized radiation at an angle to broadside from said ground plane.
Claim 2
Dependent Claim
82 words
An antenna structure comprising electrically conducting means defining a ground plane having a center line longitudinally thereof, said means having a pair of crossed slot radiators therein with the center lines of said slots crossing each other at said center line and symmetrically disposed with an angle greater than 90* therebetween at said center line, and means electrically energizing said slots ninety degrees out-ofphase to thus radiate from the slots circularly polarized radiation at an angle to broadside from said ground plane.
Claim 3
Dependent Claim
69 words
The antenna of claim 1 further defined by each of said slots making an angle of phi with the center line of said ground plane, the E field vectors of said slots making an angle Alpha 90*- phi with the center line of said ground plane and the center of said circularly polarized radiation making an angle with the ground plane of theta wherein sin theta tan Alpha /tan45*.
Claim 4
Dependent Claim
35 words
The antenna of claim 1 further defined by said ground plane being comprised as a metal layer on a dielectric plate and the means energizing said slots including microwave transmission lines coupled to separate slots.
Claim 5
Dependent Claim
18 words
The antenna of claim 1 further defined by means defining a shallow cavity disposed behind said ground plane.
Claim 6
Dependent Claim
37 words
The antenna of claim 1 further defined by each of said slots being comprised of two longitudinally aligned half-wave slot portions slightly separated at adjacent ends, and a half-wave transmission line coupling the portions of each slot.
Claim 7
Dependent Claim
90 words
An antenna structure comprising an electrically conducting ground plane having at least two slot radiators therein, said slot radiators having the center lines thereof crossing at the centers of the radiators and having an angle between the center lines greater than ninety degrees, each of said slot radiators comprising a pair of longitudinal aligned slots spaced apart at adjacent ends with the phase centers of the two radiators coincident, and means electrically energizing said slot radiators ninety degrees out of phase for propagating circularly polarized radiation from the antenna structure.
Claim 8
Dependent Claim
90 words
An antenna structure comprising an electrically conducting ground plane having at least two slot radiators therein, said slot radiators having the center lines thereof crossing at the centers of the radiators and having an angle between the center lines greater than ninety degrees, each of said slot radiators comprising a pair of longitudinal aligned slots spaced apart at adjacent ends with the phase centers of the two radiators coincident, and means electrically energizing said slot radiators ninety degrees out of phase for propagating circularly polarized radiation from the antenna structure.
Claim 9
Dependent Claim
27 words
The antenna of claim 6 further defined by a plurality of pairs of said slot radiators aligned on said ground plane to radiate in the backfire mode.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |