Patent US3902174A successfully refreshed from Google Patents.
US3902174A
Expired / Lapsed
US
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Pulsed doppler radar device having at least one range channel
Assignee: Siemens AG
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Filing: 1974-03-14
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Granted: 1975-08-26
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Expires: 1994-03-14
Abstract
Abstract A pulsed Doppler radar device with variable repetition frequency, having at least one range channel operatively connectable at the pulse rate of the pulse repetition frequency, a doppler filter which suppresses clutter interference in the low Doppler frequency range, and a device for the variation of the pulse repetition frequency, in which the doppler filter of each range channel comprises at least one sampling-and-holding circuit and a following high pass or band pass filter, the switching pulse rate of the sampling-and-holding circuit being changeable with changes in the pulse repetition frequency, with the same high pass or band filter being utilized for all repetition frequency variations, the cut-off frequency of the following filter, if a high pass filter or, the lower cut-off frequency of such filter, if a band pass filter being approximately equal to the upper frequency of the clutter band width whereby the latter is suppressed, and the upper cut-off frequency, if a band pass filter is employed, being above the maximum pulse repetition frequency.
Inventors
- 👤 Harald Siegel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:27
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/58; G01S13/64; G01S13/52; G01S13/522; G01S13/524; G01S13/526; G01S13/528
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
125 words
In a pulsed Doppler radar device with variable repetition frequency, having at least one range channel operatively connectable at the pulse rate of the pulse repetition frequency, a doppler filter which suppresses clutter interference in the low Doppler frequency range, and a device for the variation of the pulse repetition frequency, the combination of the doppler filter of each range channel comprising at least one sampling-andholding circuit and a following high pass filter, the cut-off frequency of which is approximately equal to the upper frequency of the clutter band width whereby the latter is suppressed, the switching pulse rate of the sampling-and-holding circuit being changeable with changes in the pulse repetition frequency, with the same high pass filter being utilized for all repetition frequency variations.
Claim 2
Dependent Claim
125 words
In a pulsed Doppler radar device with variable repetition frequency, having at least one range channel operatively connectable at the pulse rate of the pulse repetition frequency, a doppler filter which suppresses clutter interference in the low Doppler frequency range, and a device for the variation of the pulse repetition frequency, the combination of the doppler filter of each range channel comprising at least one sampling-andholding circuit and a following high pass filter, the cut-off frequency of which is approximately equal to the upper frequency of the clutter band width whereby the latter is suppressed, the switching pulse rate of the sampling-and-holding circuit being changeable with changes in the pulse repetition frequency, with the same high pass filter being utilized for all repetition frequency variations.
Claim 3
Dependent Claim
26 words
A pulsed Doppler radar device according to claim 1, wherein two sampling-and-holding circuits are employed, each with a cooperable filter, which circuits are connected in series.
Claim 4
Dependent Claim
34 words
A pulsed Doppler radar device according to claim 2, wherein the attenuation curve of the second filter has a steeper gradient in the area of the cut-off frequency than that of the first filter.
Claim 5
Dependent Claim
36 words
A pulsed Doppler radar device according to claim 1, wherein each range channel is provided with an input switch which is connected to the storage circuit and thus forms switching means for the associated sampling-and-holding circuit.
Claim 6
Dependent Claim
139 words
In a pulsed Doppler radar device with variable repetition frequency, having at least one range channel operatively connectable at the pulse rate of the pulse repetition frequency, a doppler filter which suppresses clutter interference in the low Doppler frequency range, and a device for the variation of the pulse repetition frequency, the combination of the doppler filter of each range channel comprising at least one sampling-and holding circuit and a following band pass filter, the lower cut-off frequency of which is approximately equal to the upper frequency of the clutter band width whereby the latter is suppressed, and the upper cut-off frequency is above the maximum pulse repetition frequency, the switching pulse rate of the sampling-and-holding circuit being changeable with changes in the pulse repetition frequency, with the same band pass filter being utilized for all repetition frequency variations.
Claim 7
Dependent Claim
139 words
In a pulsed Doppler radar device with variable repetition frequency, having at least one range channel operatively connectable at the pulse rate of the pulse repetition frequency, a doppler filter which suppresses clutter interference in the low Doppler frequency range, and a device for the variation of the pulse repetition frequency, the combination of the doppler filter of each range channel comprising at least one sampling-and holding circuit and a following band pass filter, the lower cut-off frequency of which is approximately equal to the upper frequency of the clutter band width whereby the latter is suppressed, and the upper cut-off frequency is above the maximum pulse repetition frequency, the switching pulse rate of the sampling-and-holding circuit being changeable with changes in the pulse repetition frequency, with the same band pass filter being utilized for all repetition frequency variations.
Claim 8
Dependent Claim
26 words
A pulsed Doppler radar device according to claim 2, wherein two sampling-and-holding circuits are employed, each with a cooperable filter, which circuits are connected in series.
Claim 9
Dependent Claim
35 words
A pulsed Doppler radar device according to claim 6, wherein the attenuation curve of the second filter has a steeper gradient in the area of the lower cut-off frequency than that of the first filter.
Claim 10
Dependent Claim
36 words
A pulsed Doppler radar device according to claim 5, wherein each range channel is provided with an input switch which is connected to the storage circuit and thus forms switching means for the associated sampling-and-holding circuit.
References Cited (Backward Citations)
US3742499A
Cited
US3787850A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |