US3761924A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Isolimiter
Assignee: United States Department of the Army
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Filing: 1972-09-14
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Granted: 1973-09-25
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Expires: 1992-09-14
Abstract
Abstract A ferrite isolator is combined with a ferrite-varactor limiter waveguide section to absorb reflected power without affecting microwave power signals incident to the ferrite limiter. A single magnet biases the ferrite limiter to subsidiary resonance and the ferrite isolator to main resonance. The combined isolator-limiter or isolimiter is used in a dual antenna radar system having a switched four-port circulator so that a signal from the transmitter is directed by the circulator to the selected one of the two antennas and radiated signal energy that is reflected back from the selected antenna is directed by the circulator through the isolimiter to the receiver where any spikes reflected by the varactor-limiter are absorbed by the isolator whereby varactor reflected spikes do not reach the other of the two antennas. The isolimiter affords receiver protection and isolation in one unit no larger than the limiter.
Inventors
- 👤 Gowan J Mc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:07
CPC Classifications
H; H03; H03G; H03G11/00; H03G11/006; G; G01; G01S; G01S7/00; G01S7/02; G01S7/03; G01S7/034
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
74 words
A protection device for a receiver of a radar system comprising a waveguide section including a ferrite limiter, a varactor limiter supported at the receiver end of the ferrite limiter, a ferrite isolator supported in the waveguide parallel to the ferrite limiter and in the region of circular polarization, said ferrite isolator and said ferrite limiter being substantially coextensive, and means for providing magnetic bias to said ferrite limiter and to said ferrite isolator.
Claim 2
Dependent Claim
74 words
A protection device for a receiver of a radar system comprising a waveguide section including a ferrite limiter, a varactor limiter supported at the receiver end of the ferrite limiter, a ferrite isolator supported in the waveguide parallel to the ferrite limiter and in the region of circular polarization, said ferrite isolator and said ferrite limiter being substantially coextensive, and means for providing magnetic bias to said ferrite limiter and to said ferrite isolator.
Claim 3
Dependent Claim
53 words
A protection device for a receiver of a radar system as defined in claim 1 wherein said means for providing magnetic bias is a single magnet and a magnetic shunt that provides the field intensity across said ferrite limiter for secondary resonance limiting and the field intensity across said isolator for main resonance.
Claim 4
Dependent Claim
174 words
In a radar system the combination which comprises a four port circulator, two antennas coupled to two of the ports of the circulator, a transmitter coupled to a third port of the circulator, a receiver coupled to the fourth port, said circulator being controllable to direct signal power output of said transmitter to either of said antenna ports and for directing energy returned from either antenna port to the fourth port, said circulator being operable to direct any energy returned by the receiver port to that one of the two antenna ports other than the one that delivered that energy to the receiver port, a waveguide section having a flange at each end, in series with said receiver port and including a ferrite limiter, a varactor limiter supported at the receiver end of the ferrite limiter, a ferrite-isolator supported in the waveguide parallel to the ferrite limiter and substantially coextensive therewith, and magnetic bias means for said ferrite limiter and said ferrite isolator supported by the exterior of said waveguide section between the flanges.
Claim 5
Dependent Claim
174 words
In a radar system the combination which comprises a four port circulator, two antennas coupled to two of the ports of the circulator, a transmitter coupled to a third port of the circulator, a receiver coupled to the fourth port, said circulator being controllable to direct signal power output of said transmitter to either of said antenna ports and for directing energy returned from either antenna port to the fourth port, said circulator being operable to direct any energy returned by the receiver port to that one of the two antenna ports other than the one that delivered that energy to the receiver port, a waveguide section having a flange at each end, in series with said receiver port and including a ferrite limiter, a varactor limiter supported at the receiver end of the ferrite limiter, a ferrite-isolator supported in the waveguide parallel to the ferrite limiter and substantially coextensive therewith, and magnetic bias means for said ferrite limiter and said ferrite isolator supported by the exterior of said waveguide section between the flanges.
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) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |