Patent US3720816A successfully refreshed from Google Patents.
US3720816A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for fourier analysis of interference signals
Assignee: Spectrospin AG
•
Filing: 1970-11-06
•
Granted: 1973-03-13
•
Expires: 1990-11-06
Abstract
Abstract Interference signals such as those obtained in nuclear spin spectrometry are subjected to a Fourier analysis in which the frequencies and amplitudes of the interference signals are determined mathematically. The excitation of the sample produces interference signals, all the oscillations of a definite frequency band are filtered out, and the Fourier analysis is performed on this frequency band. The selected portion of the interference oscillations is varied by varying the frequency band and the center frequency thereof in reference to the frequency content of the whole interference signal. One frequency may be produced in a fundamental oscillator and various frequencies, for example for use in mixing circuits, are obtained by frequency multiplication and division.
Inventors
- 👤 T Keller
- 👤 G Laukien
- 👤 W Tschopp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:52
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/46; G01R33/4625; G01R33/28; G01R33/32; G01R33/36; G01R33/3607
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
75 words
Apparatus for the Fourier analysis of interference signals comprising generator means for producing at least one local oscillation frequency, mixer means to which the interference signal and said at least one local oscillation frequency produced by said generator means are supplied for converting said interference signal into suitable intermediate frequency bands, and filter means for filtering out definite frequency bands from said interference signal after conversion into suitable intermediate frequency bands by said mixer means.
Claim 2
Dependent Claim
75 words
Apparatus for the Fourier analysis of interference signals comprising generator means for producing at least one local oscillation frequency, mixer means to which the interference signal and said at least one local oscillation frequency produced by said generator means are supplied for converting said interference signal into suitable intermediate frequency bands, and filter means for filtering out definite frequency bands from said interference signal after conversion into suitable intermediate frequency bands by said mixer means.
Claim 3
Dependent Claim
75 words
Apparatus for the Fourier analysis of interference signals comprising generator means for producing at least one local oscillation frequency, mixer means to which the interference signal and said at least one local oscillation frequency produced by said generator means are supplied for converting said interference signal into suitable intermediate frequency bands, and filter means for filtering out definite frequency bands from said interference signal after conversion into suitable intermediate frequency bands by said mixer means.
Claim 4
Dependent Claim
75 words
Apparatus for the Fourier analysis of interference signals comprising generator means for producing at least one local oscillation frequency, mixer means to which the interference signal and said at least one local oscillation frequency produced by said generator means are supplied for converting said interference signal into suitable intermediate frequency bands, and filter means for filtering out definite frequency bands from said interference signal after conversion into suitable intermediate frequency bands by said mixer means.
Claim 5
Dependent Claim
15 words
Apparatus according to claim 1, wherein said mixer means includes at least one phase detector.
Claim 6
Dependent Claim
60 words
Apparatus according to Claim 1, wherein said mixer means comprises two successively connected mixers to each of which a local frequency is supplied by said generator means, which local frequency lies below a particular interference signal frequency and wherein the first mixer is followed by a band pass filter, and the second mixer is followed by a low pass filter.
Claim 7
Dependent Claim
91 words
Apparatus according to Claim 1, wherein said generator means includes a highly stable generator section which produces a first local frequency adjacent to the frequencies of the interference signal and a local oscillator and wherein said mixer means includes two mixers to both of which a second local frequency of the local oscillator is supplied and one of which receives the interference signal and the other the first local frequency and wherein the intermediate frequency signals formed in the two mixers are supplied to a further mixer of the mixer means.
Claim 8
Dependent Claim
37 words
Apparatus according to claim 4, wherein said generator means comprises a fundamental oscillator, first, second and third frequency synthesizer means respectively controlled by said fundamental oscillator for supplying the various local frequencies, excitation frequencies and repetition frequencies.
Claim 9
Dependent Claim
39 words
Apparatus according to claim 1, wherein said generator means for at least one of the required frequencies each comprises an oscillator and the oscillators are difference-stabilized with reference to a fundamental oscillator formed by each of the oscillators used.
Claim 10
Dependent Claim
29 words
Apparatus according to claim 1, wherein means for Fourier analysis of said filtered out bands, in particular a programmed computer, is connected to the output of said filtering means.
Claim 11
Dependent Claim
27 words
An apparatus according to claim 4, including means for amplifying the outputs of said two mixers prior to the supplying of the outputs to said further mixer.
Claim 12
Dependent Claim
47 words
An apparatus according to claim 5, wherein one of said frequency synthesizer means includes arithmetic circuitry, responsive to the output of said second frequency synthesizer means and said fundamental oscillator for generating said repetitive frequency, including a first difference generator and a divider circuit connected in series.
Claim 13
Dependent Claim
54 words
An apparatus according to claim 9, wherein said third frequency synthesizer means further includes a multiplier and a second difference generator connected in series to the output of said divider, said second difference generator receiving the output of said frequency synthesizer means for generating a further oscillator signal supplied to said further mixer means.
Claim 14
Dependent Claim
76 words
In a method of Fourier analysis of interference signals, especially those corresponding to interferograms such as are obtained in spin resonance spectrometry, the improvement comprising the steps of: a. filtering out all oscillations from an interference signal of a predetermined frequency band included in the spectrum within which said interference signals lie; and b. carrying out Fourier analysis on said filtered out frequency band by determining the frequencies and amplitudes of said filtered out oscillations mathmatically.
Claim 15
Dependent Claim
76 words
In a method of Fourier analysis of interference signals, especially those corresponding to interferograms such as are obtained in spin resonance spectrometry, the improvement comprising the steps of: a. filtering out all oscillations from an interference signal of a predetermined frequency band included in the spectrum within which said interference signals lie; and b. carrying out Fourier analysis on said filtered out frequency band by determining the frequencies and amplitudes of said filtered out oscillations mathmatically.
Claim 16
Dependent Claim
43 words
A method according to claim 11, wherein said step (a) comprises the steps of: selecting a frequency band with reference to the frequency content of an entire interference signal; and varying the frequency band and the center frequency of said selected frequency band.
Claim 17
Dependent Claim
58 words
A method according to claim 11, wherein step (a) is carried out for repeatedly obtained interference signals from which an average value is obtained, so that said filtered out oscillations correspond to said frequency band for said average value and further including the step of storing said filtered out signal prior to said step (b) of Fourier analysis.
Claim 18
Dependent Claim
46 words
A method according to claim 11, further comprising the step of repeating step (a) and storing the filtered out oscillations after each repetition to form an average value of a filtered-out oscillation prior to the step (b) of carrying out Fourier analysis on said average value.
Claim 19
Dependent Claim
35 words
A method according to claim 11, wherein step (a) includes the step of converting said interference signal into a predetermined intermediate frequency band by mixing said interference signal with at least one local oscillation frequency.
Claim 20
Dependent Claim
39 words
A method according to claim 15, wherein said step of converting further includes varying the center frequency of said predetermined frequency band with reference to the frequency content of the entire interference signal by varying said local oscillation frequency.
Claim 21
Dependent Claim
48 words
A method according to claim 15, in which the ratio between the magnetic measuring field and the reference frequency is stabilized by the application of a spin resonance reference frequency, comprising the steps of maintaining the difference between the local oscillation frequency and said reference frequency approximately constant.
Claim 22
Dependent Claim
61 words
A method according to claim 17, wherein said step (a) further comprises the step of stabilizing said interference signal and said one local oscillation frequency to provide a first additional mixed frequency and mixing said one local oscillation frequency with said additional local oscillation frequency to provide a second additional mixed frequency and mixing said first and second additional mixed frequencies.
Claim 23
Dependent Claim
40 words
A method according to claim 15, wherein said local oscillation frequency lies outside one of: (i) the band within which the oscillation frequencies of said interference signal lie, and (ii) a previously filtered out frequency band of the interference signal.
Claim 24
Dependent Claim
91 words
A method according to claim 19, wherein said step (a) further comprises filtering out the first frequency band of signals from said predetermined intermediate frequency band subsequent to the step of converting, with respect to which the limit adjacent said local frequency has a greater spacing than the interference signal and then converting said filtered out first frequency band of signals into a predetermined lower frequency band by combining said filtered out first frequency band with a second local oscillator frequency closely adjacent to the limit of said first frequency band.
Claim 25
Dependent Claim
82 words
A method according to claim 20, wherein step (a) is carried out for repeatedly obtained interference signals from which an average value is obtained, so that said filtered out oscillations correspond to said frequency band for said average value and further including the step of storing said filtered out signal prior to said step of Fourier analysis, and wherein Said second local oscillator frequency is formed from a single multiple of the repetitive frequency at which said interference signal is repeatedly obtained.
Claim 26
Dependent Claim
47 words
A method according to claim 21, including the steps of exciting spin resonance by the generation of high frequency pulses and wherein the spacing of said second local oscillator frequency from the carrier frequency of said high frequency pulses is a simple multiple of the repetitive frequency.
Claim 27
Dependent Claim
21 words
A method according to claim 22, comprising the step of generating high frequency pulses from a single source of carrier signals.
Claim 28
Dependent Claim
23 words
A method according to claim 22, wherein the repetitive frequency is a simple fraction of the carrier frequency of said high frequency pulses.
Claim 29
Dependent Claim
16 words
A method according to claim 24, further comprising the step of varying said repetitive frequencies statistically.
Claim 30
Dependent Claim
26 words
A method according to claim 24, further comprising statistically varying said repetitive frequency as a simple fraction of said carrier frequency of said high frequency pulses.
Claim 31
Dependent Claim
49 words
A method according to claim 13, further comprising exciting spin resonances by the application of high frequency pulses having a predetermined carrier frequency which has an approximately constant spacing with respect to the reference frequency for said spin resonances and falls within the frequency spectrum of said interference signals.
References Cited (Backward Citations)
US3475680A
Cited
US3495162A
Cited
US3564399A
Cited
US3581193A
Cited
US3530371A
Cited
US3581191A
Cited
US3588678A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |