Patent US2704071A successfully refreshed from Google Patents.
US3742437A
Expired / Lapsed
US
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Signal transmission system
Assignee: Fried Krupp AG
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Filing: 1972-02-29
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Granted: 1973-06-26
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Expires: 1992-02-29
Abstract
Abstract A frequency keyed signal system having a transmitter which generates and transmits coded frequency keyed signals having a sequence of intervals of identical time durations. A plurality of different frequencies are utilized, each of the frequencies being a respective whole positive number multiple of a fundamental frequency. A receiver responsive to the transmitted coded frequency keyed signals is provided. The receiver includes a frequency divider responsive to the received signals. The frequency divider has a variable dividing ratio and produces on its output an output signal of the fundamental frequency with any Doppler shift as may be present. A frequency analyzer is coupled to the output of the frequency divider and is responsive to its output signal.
Inventors
- 👤 R Thiele
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:51
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/58; G01S13/583; G01R; G01R23/00; G01R23/005
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
175 words
In a frequency keyed signal system having transmitter means for transmitting signals which have been frequency keyed according to any desirable code and are of a sequence of intervals having substantially identical time durations, the frequencies of the transmitter signals differing from one another and being multiples of a fundamental frequency, and receiving means responsive to the transmitted signals, said receiving means including means for determining Doppler shift, the improvement comprising means forming part of said transmitter means for producing said transmitted signals of different respective frequencies so that said frequencies are whole positive number multiples of said fundamental frequency; wherein said receiving means includes frequency dividing means responsive to the received signals and having a variable dividing ratio for producing on its output an output signal of the fundamental frequency with any Doppler shift as may be present; and wherein said means for determining Doppler shift comprises frequency analyzer means which is tuned to said fundamental frequency and is coupled to the output of said frequency divider means and responsive to its output signal.
Claim 2
Dependent Claim
175 words
In a frequency keyed signal system having transmitter means for transmitting signals which have been frequency keyed according to any desirable code and are of a sequence of intervals having substantially identical time durations, the frequencies of the transmitter signals differing from one another and being multiples of a fundamental frequency, and receiving means responsive to the transmitted signals, said receiving means including means for determining Doppler shift, the improvement comprising means forming part of said transmitter means for producing said transmitted signals of different respective frequencies so that said frequencies are whole positive number multiples of said fundamental frequency; wherein said receiving means includes frequency dividing means responsive to the received signals and having a variable dividing ratio for producing on its output an output signal of the fundamental frequency with any Doppler shift as may be present; and wherein said means for determining Doppler shift comprises frequency analyzer means which is tuned to said fundamental frequency and is coupled to the output of said frequency divider means and responsive to its output signal.
Claim 3
Dependent Claim
71 words
An arrangement as defined in claim 1 wherein said frequency divider meaNs comprises filter means and monostable multivibrator means, said monostable multivibrator means having a constant period of dwell in its astable state which is shorter than said time duration of the individual intervals of the sequence of transmitted frequency signals and said filter means being coupled to the output of said monostable multivibrator means and responsive to its output signal.
Claim 4
Dependent Claim
49 words
Arrangement as defined in claim 2 wherein said monostable multivibrator means has a period of dwell which is equal to the reciprocal value of the arithmetical mean frequency of two adjacent multiples of said fundamental frequency which reciprocal value is multiplied by the smaller one of two adjacent multiples.
Claim 5
Dependent Claim
45 words
An arrangement as defined in claim 2 wherein said filter means comprises bandpass filter means whose center frequency is substantially equal to said fundamental frequency, said frequency analyzer means being coupled to the output of said bandpass filter means and responsive to its output signal.
Claim 6
Dependent Claim
30 words
An arrangement as defined in claim 4 wherein said frequency analyzer means comprises a filter bank, the output signal from the filter bank being a measure of the Doppler shift.
Claim 7
Dependent Claim
33 words
An arrangement as defined in claim 2 wherein said receiving means further includes flip-flop means responsive to the received signals and having its output coupled to the input of said monostable multivibrator means.
References Cited (Backward Citations)
US3436721A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |