US4821046A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual band feed system
Assignee: Individual
•
Filing: 1987-04-06
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Granted: 1989-04-11
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Expires: 2007-04-06
Abstract
Abstract A dual frequency band microwave antenna feed for a parabolic reflector has a circular waveguide for a low frequency band and a smaller circular waveguide for a higher frequency band disposed in and concentric with the low band guide. A twisted conductive baffle is disposed in each guide to permit 90° rotation of linearly cross-polarization signals and a pair of in-line ports is attached to each guide for output of such pairs of cross-polarization signals.
Inventors
- 👤 Brian J. Wilkes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:03
CPC Classifications
H; H01; H01Q; H01Q5/00; H01Q5/40; H01Q5/45; H01Q5/47
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
198 words
A dual frequency band microwave antenna feed for a parabolic reflector comprising: a first circular waveguide having a diameter for supporting first electromagnetic waves of a first microwave frequency range in the TE 01 mode; a second circular waveguide disposed concentrically with said first circular waveguide for supporting second electromagnetic waves of a second microwave frequency range, higher in frequency than the first microwave frequency range, in the TE 01 mode, a rearward portion of said second circular waveguide extending from a rearward end of said first waveguide; a first one of a first pair of in-line ports disposed in said first circular waveguide for output of a first one of a first pair of linearly cross-polarized electromagnetic waves; first polarization rotation means for rotating the planes of said first linearly cross-polarized electromagnetic waves rearward of said first port in said first waveguide; a first one of a second pair of in-line ports disposed in said second waveguide for output of a first one of a second pair of linearly cross-polarized electromagnetic waves; and second polarization rotation means for rotating the planes of said second linearly cross-polarized electromagnetic waves rearward of said first port in said second waveguide.
Claim 2
Dependent Claim
198 words
A dual frequency band microwave antenna feed for a parabolic reflector comprising: a first circular waveguide having a diameter for supporting first electromagnetic waves of a first microwave frequency range in the TE 01 mode; a second circular waveguide disposed concentrically with said first circular waveguide for supporting second electromagnetic waves of a second microwave frequency range, higher in frequency than the first microwave frequency range, in the TE 01 mode, a rearward portion of said second circular waveguide extending from a rearward end of said first waveguide; a first one of a first pair of in-line ports disposed in said first circular waveguide for output of a first one of a first pair of linearly cross-polarized electromagnetic waves; first polarization rotation means for rotating the planes of said first linearly cross-polarized electromagnetic waves rearward of said first port in said first waveguide; a first one of a second pair of in-line ports disposed in said second waveguide for output of a first one of a second pair of linearly cross-polarized electromagnetic waves; and second polarization rotation means for rotating the planes of said second linearly cross-polarized electromagnetic waves rearward of said first port in said second waveguide.
Claim 3
Dependent Claim
47 words
The antenna feed as recited in claim 1 in which: said first polarization rotation means includes a first twisted conductive baffle between said first pair of in-line ports; and said second polarization rotation means includes a second twisted conductive baffle between said second pair of in-line ports.
Claim 4
Dependent Claim
29 words
The antenna feed as recited in claim 1 which further includes a circular scalar feed network disposed concentrically with and at a forward end of said first circular waveguide.
Claim 5
Dependent Claim
20 words
The antenna feed as recited in claim 3 in which said first circular waveguide protrudes from said scalar feed network.
Claim 6
Dependent Claim
43 words
The antenna feed as recited in claim 4 in which the protrusion of said first circular waveguide from said scalar feed network is controllable for adjusting the aperture illumination of said antenna feed for said parabolic reflector for said first microwave frequency range.
Claim 7
Dependent Claim
28 words
The antenna feed as recited in claim 1 in which a forward portion of said second circular waveguide protrudes from a forward end of said first circular waveguide.
Claim 8
Dependent Claim
46 words
The antenna feed as recited in claim 6 in which the protrusion of said second circular waveguide from the forward end of said first waveguide is controllable for adjusting the aperture illumination of said antenna feed for said parabolic reflector for said second microwave frequency range.
Claim 9
Dependent Claim
36 words
The antenna feed as recited in claim 1 in which the outside diameter of said second circular waveguide is selected to coincide with a null area of the TE 01 mode in said first circular waveguide.
Claim 10
Dependent Claim
31 words
The antenna feed as recited in claim 8 in which the inside diameter of said second circular waveguide is selected to support the TE 01 mode for said second frequency range.
Claim 11
Dependent Claim
22 words
The antenna feed as recited in claim 1 in which said first frequency range is between at least 3.7 to 4.2 GHz.
Claim 12
Dependent Claim
22 words
The antenna feed as recited in claim 10 in which said second frequency range is between at least 9.0 to 15.0 GHz.
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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) | 1992-04-10 | 1992-10-10 | 1993-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-10 | 1996-10-10 | 1997-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-10 | 2000-10-10 | 2001-04-11 | $7700.00 | Window Closed / Lapsed |