Patent US3774223A successfully refreshed from Google Patents.
US3774223A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-frequency waveguide feed in combination with a short-backfire antenna
Assignee: United States Department of the Air Force
•
Filing: 1972-10-04
•
Granted: 1973-11-20
•
Expires: 1992-10-04
Abstract
Abstract A high-frequency waveguide feed in combination with a shortbackfire antenna having a cavity and multiple reflectors to permit high power handling capabilities and high frequency applications. An open end of a waveguide is used as the primary radiator in the antenna cavity. The waveguide intrudes into the cavity from behind the larger reflector plate. The polarization response of the antenna is determined by the type of waveguide chosen.
Inventors
- 👤 H Ehrenspeck
- 👤 J Strom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:16
CPC Classifications
H; H01; H01Q; H01Q19/00; H01Q19/10; H01Q19/18; H01Q19/185
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
127 words
A high frequency waveguide feed in combination with a shortbackfire antenna comprising a full reflector having a hole therethrough of a preselected dimension, a partial reflector spaced at a preselected distance from said full reflector, the spacing between reflectors being substantially an integral multiple of an electrical half wavelength to produce a resonant cavity thus providing a standing wave such that the field slowly decays from its maximum value on the antenna axis and being everywhere approximately in phase, a waveguide feed of a preselected dimension slightly smaller than said preselected dimension of said hole passing through said hole in said full reflector permitting said open end thereof to intrude into said resonant cavity, the configuration of said waveguide feed determining the polarization of said short-backfire antenna.
Claim 2
Dependent Claim
127 words
A high frequency waveguide feed in combination with a shortbackfire antenna comprising a full reflector having a hole therethrough of a preselected dimension, a partial reflector spaced at a preselected distance from said full reflector, the spacing between reflectors being substantially an integral multiple of an electrical half wavelength to produce a resonant cavity thus providing a standing wave such that the field slowly decays from its maximum value on the antenna axis and being everywhere approximately in phase, a waveguide feed of a preselected dimension slightly smaller than said preselected dimension of said hole passing through said hole in said full reflector permitting said open end thereof to intrude into said resonant cavity, the configuration of said waveguide feed determining the polarization of said short-backfire antenna.
Claim 3
Dependent Claim
31 words
A high frequency waveguide feed in combination with a short-backfire antenna as described in claim 1 further including a reflecting rim surrounding said full reflector, said rim having a preselected width.
Claim 4
Dependent Claim
41 words
A high frequency waveguide feed in combination with a short-backfire antenna as described in claim 2 further including means connected between said reflecting rim and said partial reflector to support said partial reflector at said preselected distance from said full reflector.
Claim 5
Dependent Claim
41 words
A high frequency waveguide feed in combination with a short-backfire antenna as described in claim 3 wherein said connecting means is comprised of metal rods utilized only during linear polarization, said metal rods being arranged transverse to the plane of polarization.
Claim 6
Dependent Claim
32 words
A high frequency waveguide feed in combination with a short-backfIre antenna as described in claim 3 where said connecting means is comprised of rods of nonconducting material utilized exclusively during cross polarization.
Claim 7
Dependent Claim
30 words
A high frequency waveguide feed in combination with a short-backfire antenna as described in claim 1 further including a flange connected to said full reflector to support said waveguide feed.
Claim 8
Dependent Claim
28 words
A high frequency waveguide feed in combination with a short-backfire antenna as described in claim 1 wherein said waveguide feed is rectangular to provide a first predetermined polarization.
Claim 9
Dependent Claim
28 words
A high frequency waveguide in combination with a short backfire antenna as described in claim 2 wherein said waveguide feed is circular to provide a second predetermined polarization.
Claim 10
Dependent Claim
36 words
A high frequency waveguide feed in combination with a short-backfire antenna as described in claim 3 wherein said open end of said waveguide feed is located approximately midway between said full reflector and said partial reflector.
Claim 11
Dependent Claim
31 words
A high frequency waveguide in combination with a short-backfire antenna as described in claim 2 wherein said open end of said waveguide is located in the plane of said full reflector.
Claim 12
Dependent Claim
50 words
A high frequency waveguide feed in combination with a short-backfire antenna as described in claim 10 further including a second partial reflector approximately of the same dimension of the first utilized partial reflector and positioned approximately midway between said open end of said waveguide and the first utilized partial reflector.
Claim 13
Dependent Claim
37 words
A high frequency waveguide feed in combination with a short-backfire antenna as described in claim 11 further including support means for said second partial reflector connected between said first utilized partial reflector and said second partial reflector.
Claim 14
Dependent Claim
25 words
A high frequency waveguide feed in combination with a short-backfire antenna as described in claim 12 wherein said waveguide feed consists of a rectangular configuration.
Claim 15
Dependent Claim
25 words
A high frequency waveguide feed in combination with a short-backfire antenna as described in claim 12 wherein said backfire feed consists of a circular configuration.
Claim 16
Dependent Claim
124 words
Short-backfire antenna arrays with waveguide feeds comprising a common full reflector having a multiplicity of holes therethrough, each of the holes being of a predetermined dimension, a reflecting rim of preselected width surrounding and connected to said common full reflector, a multiplicity of partial reflectors, means to space each of said reflectors being positioned opposite to an associated hole and at a preselected distance from said common reflector to form a resonant cavity, and a multiplicity of waveguide feeds, each having a preselected dimension slightly smaller than the preselected dimension of an associated hole and each also having an open end, each of said waveguide feeds passing through an associated hole to permit the open end thereof to intrude into an associated resonant cavity.
Claim 17
Dependent Claim
124 words
Short-backfire antenna arrays with waveguide feeds comprising a common full reflector having a multiplicity of holes therethrough, each of the holes being of a predetermined dimension, a reflecting rim of preselected width surrounding and connected to said common full reflector, a multiplicity of partial reflectors, means to space each of said reflectors being positioned opposite to an associated hole and at a preselected distance from said common reflector to form a resonant cavity, and a multiplicity of waveguide feeds, each having a preselected dimension slightly smaller than the preselected dimension of an associated hole and each also having an open end, each of said waveguide feeds passing through an associated hole to permit the open end thereof to intrude into an associated resonant cavity.
Claim 18
Dependent Claim
28 words
Short-backfire antenna arrays with waveguide feeds as described in claim 15 wherein said space means is comprised of rods connected between said partial reflectors and said reflecting rim.
Claim 19
Dependent Claim
37 words
Short-backfire antenna arrays with waveguide feeds as described in claim 15 wherein each of said open ends intrudes into an associated resonant cavity at a distance approximately midway between said common reflector and the associated partial reflector.
References Cited (Backward Citations)
US3122745A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |