US3725926A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency diversified radar system
Assignee: United States Department of the Air Force
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Filing: 1969-03-11
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Granted: 1973-04-03
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Expires: 1989-03-11
Abstract
Abstract A frequency diversity moving target indicator radar system utilizing a combination of coherent and incoherent processing to improve performance in clutter interference, including a multiple frequency waveform which is processed in a multiple channel receiver and further including a frequency multiplexer, a broad band delay line IF canceller and a demultiplexer. Normalizers producing digital signals, and digital delays for aligning the signals in the time domain combine with a binomial detector to produce target information.
Inventors
- 👤 M Ares
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:29
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/52; G01S13/522; G01S13/524; G01S13/526; G01S13/5265; G01S13/534; G01S7/00; G01S7/02; G01S7/42
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
115 words
A receiver for processing input signals in a frequency diversified doppler radar system comprising: means for receiving and amplifying the input signals; means for dividing the signals into separate frequency groupings; a plurality of mixers, including local oscillators to produce intermediate frequencies connected to the dividing means; a frequency multiplexer to recombine the divided signals; means connected to the multiplexer for cancelling undesired signals; a frequency demultiplexer connected to said cancelling means for separating the said signals into frequency groupings; means to detect and normalize each of said frequency groupings, and digital detector means connected to the normalizing means for indicating the presence of a target when a preset number of input pulses are present.
Claim 2
Dependent Claim
115 words
A receiver for processing input signals in a frequency diversified doppler radar system comprising: means for receiving and amplifying the input signals; means for dividing the signals into separate frequency groupings; a plurality of mixers, including local oscillators to produce intermediate frequencies connected to the dividing means; a frequency multiplexer to recombine the divided signals; means connected to the multiplexer for cancelling undesired signals; a frequency demultiplexer connected to said cancelling means for separating the said signals into frequency groupings; means to detect and normalize each of said frequency groupings, and digital detector means connected to the normalizing means for indicating the presence of a target when a preset number of input pulses are present.
Claim 3
Independent Claim
88 words
A method of suppressing interference in radar systems including the steps of transmitting a series of multiple frequency pulses at regular intervals; receiving the echo pulses; separating the received pulses into frequency groupings; mixing and amplifying the frequency groupings to produce an intermediate frequency; recombining the frequency groupings; eliminating the undesired signals; reseparating the signals into frequency groupings; obtaining video signals based on frequency groupings; converting the video signals into digital signals and detecting the digital signals to indicate the presence of a target without regard to interference.
Claim 4
Independent Claim
88 words
A method of suppressing interference in radar systems including the steps of transmitting a series of multiple frequency pulses at regular intervals; receiving the echo pulses; separating the received pulses into frequency groupings; mixing and amplifying the frequency groupings to produce an intermediate frequency; recombining the frequency groupings; eliminating the undesired signals; reseparating the signals into frequency groupings; obtaining video signals based on frequency groupings; converting the video signals into digital signals and detecting the digital signals to indicate the presence of a target without regard to interference.
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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |