US3696434A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Independent mode antenna feed system
Assignee: Radiation Inc
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Filing: 1971-01-15
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Granted: 1972-10-03
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Expires: 1991-01-15
Abstract
Abstract A feed system for autotracking antennas, in which the transmit channel and the receive sum and difference channels are independently controllable in that each is isolated from the other and the impedance match of any one is adjustable without disturbing the other two. The receive wave modes, both sum and difference, are propagated along a first section of waveguide from the antenna, wherein the receive channel energy is extracted near an abrupt junction with a second waveguide section designed to support only sum wave mode propagation. The sum mode is extracted without need for hybrids. The transmit feed and the receive feed lines cooperate to provide built-in diplexer action through appropriate selection of waveguide dimensions for rejection of transmit frequencies from the receive channel and inclusion of band pass filters for rejection of receive frequencies from the transmit channel.
Inventors
- 👤 Anttilio F Sciambi Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:59
CPC Classifications
H; H01; H01Q; H01Q25/00; H01Q25/04; H01Q25/02
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
144 words
A feed arrangement for autotracking antenna systems, said feed arrangement having a main receive channel for energy in a receive frequency band incident on the antenna, said main receive channel comprising a waveguide characterized by a section of large inside transverse dimensions and a section of relatively smaller inside transverse dimensions, said sections joined together at an abrupt axially symmetrical junction, said smaller dimensioned waveguide section selected to support virtually only sum mode propagation, said larger dimensioned waveguide section selected to support both sum and difference mode propagation, means for feeding energy in said receive band from said antenna into said larger dimensioned waveguide section, and means located in a plane an odd number of quarter wavelengths from said junction in said larger dimensioned waveguide section, at approximately the wavelength of the difference mode wave, for extracting the difference mode energy from said waveguide.
Claim 2
Dependent Claim
144 words
A feed arrangement for autotracking antenna systems, said feed arrangement having a main receive channel for energy in a receive frequency band incident on the antenna, said main receive channel comprising a waveguide characterized by a section of large inside transverse dimensions and a section of relatively smaller inside transverse dimensions, said sections joined together at an abrupt axially symmetrical junction, said smaller dimensioned waveguide section selected to support virtually only sum mode propagation, said larger dimensioned waveguide section selected to support both sum and difference mode propagation, means for feeding energy in said receive band from said antenna into said larger dimensioned waveguide section, and means located in a plane an odd number of quarter wavelengths from said junction in said larger dimensioned waveguide section, at approximately the wavelength of the difference mode wave, for extracting the difference mode energy from said waveguide.
Claim 3
Dependent Claim
66 words
The feed arrangement according to claim 1 wherein said larger dimensioned section supports two diverse difference modes, and wherein second extracting means is located in a plane an odd number of quarter wavelengths back from said junction in said larger dimensioned waveguide section, at approximately the wavelength of the second of the difference mode waves, for extracting energy in the second difference mode from said waveguide.
Claim 4
Dependent Claim
42 words
The feed arrangement according to claim 2, further including means for combining the difference mode energy extracted from said waveguide by both of said extracting means, to derive information regarding the location of a target being tracked by the autotracking antenna system.
Claim 5
Dependent Claim
34 words
The feed arrangement according to claim 3, further including means for removing sum mode energy from said smaller dimensioned waveguide section after passage of the sum mode energy through said larger dimensioned waveguide section.
Claim 6
Dependent Claim
39 words
The feed arrangement according to claim 4, wherein said combining means includes means for rejecting sum mode energy coupled into the difference mode extracting means, for recovery of said coupled energy by said means for removing sum mode energy.
Claim 7
Dependent Claim
29 words
The feed arrangement according to claim 5, further including means coupled to said extracting means and to said removing means, for circular polarization of the sum and difference signals.
Claim 8
Dependent Claim
50 words
The feed arrangement according to claim 1, wherein said energy feeding means includes means for supplying energy in a transmit frequency band to said antenna, and means for isolating energy in the transmit band from the receive channel and for isolating energy in the receive band from the transmit channel.
Claim 9
Dependent Claim
24 words
The feed arrangement according to claim 2, wherein each of said extracting means includes energy absorbing probes projecting into said larger dimensioned waveguide section.
Claim 10
Dependent Claim
157 words
An antenna feed system for independent control of sum and difference channels, comprising first and second serially connected electromagnetic wave transmission lines constructed and arranged to receive energy absorbed by an antenna in a predetermined receive frequency band and to support wave modes of propagation associated with sum and difference information in the absorbed energy, said second transmission line constructed and arranged to receive energy passing through said first transmission line and to support only the wave propagation mode associated with the sum information, means between said first and second transmission lines for preventing the entry of the wave propagation modes associated with the difference information from said first transmission line into said second transmission line, means coupled to said first transmission line for extracting energy from the wave propagation modes associated with the difference information, and means coupled to said second transmission line for extracting energy from the wave propagation mode associated with the sum information.
Claim 11
Dependent Claim
157 words
An antenna feed system for independent control of sum and difference channels, comprising first and second serially connected electromagnetic wave transmission lines constructed and arranged to receive energy absorbed by an antenna in a predetermined receive frequency band and to support wave modes of propagation associated with sum and difference information in the absorbed energy, said second transmission line constructed and arranged to receive energy passing through said first transmission line and to support only the wave propagation mode associated with the sum information, means between said first and second transmission lines for preventing the entry of the wave propagation modes associated with the difference information from said first transmission line into said second transmission line, means coupled to said first transmission line for extracting energy from the wave propagation modes associated with the difference information, and means coupled to said second transmission line for extracting energy from the wave propagation mode associated with the sum information.
Claim 12
Dependent Claim
66 words
The antenna feed system of claim 9, further including a third transmission line connecting said first transmission line to said antenna, a fourth transmission line connected to said third transmission line for supplying power in a transmit frequency band to said antenna, and means associated with said third and fourth transmission lines for isolating the transmit channel from the receive channel to retard energy transfer therebetween.
Claim 13
Dependent Claim
16 words
The antenna feed system of claim 9 wherein said first and second transmission lines are waveguides.
Claim 14
Dependent Claim
39 words
The antenna feed system of claim 11 wherein said means between said first and second transmission lines is an axially symmetrical abrupt waveguide junction presenting an effective short circuit to the wave propagation modes associated with the difference information.
Claim 15
Dependent Claim
29 words
The antenna feed system of claim 12 wherein the sum mode is the TE10 mode, and the difference modes are the TE11 + TM11 mode and the TE20 mode.
Claim 16
Dependent Claim
95 words
The antenna feed system of claim 13 wherein said means coupled to said first transmission line for extracting energy comprises a first set of probes projecting into the waveguide in a plane located an odd number of quarter wavelengths from said junction, at the guide wavelength for the TE11 + 11 mode, for absorbing energy from that mode, and a second set of probes projecting into the waveguide in a plane located an odd number of quarter wavelengths from said junction, at the guide wavelength for the TE20 mode, for absorbing energy from that mode.
Claim 17
Dependent Claim
69 words
The antenna feed system of claim 11 wherein said fourth transmission line includes wave filter means for passing said transmit frequency band while rejecting frequencies outside said transmit frequency band, said first and second transmission lines having dimensions selected to reject said transmit frequency band while passing said receive frequency band, and cooperating with said wave filter means in said fourth traNsmission line to act as a built-in diplexer.
Claim 18
Dependent Claim
48 words
The antenna feed system of claim 10 wherein each of the transmit channel and the receive sum and difference channels has an impedance match at its respective frequency band which is independent of the impedance match presented by the others of said channels at their respective frequency bands.
References Cited (Backward Citations)
US2759154A
Cited
US3423756A
Cited
US3373431A
Cited
US3383688A
Cited
US3369197A
Cited
US3388399A
Cited
US3530483A
Cited
US3560976A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |