US3581191A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phase correlation for an rf spectrometer employing an rf carrier modulated by a pseudorandom sequence
Assignee: Varian Medical Systems Inc
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Filing: 1969-08-06
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Granted: 1971-05-25
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Expires: 1989-08-06
Abstract
Abstract The radio frequency spectrometer is disclosed employing a radio frequency transmitter which transmits a wide band of energy to the sample for simultaneously exciting radio frequency resonance of different spectral lines of the sample. The wide band transmitter energy is generated by a radio frequency carrier which is modulated by a pseudorandom binary sequence to produce the wide bandwidth for exciting the sample. The pseudorandom binary sequence is repetitive and the excited composite resonance signal is repetitively time scanned and sampled at a multiplicity of intervals during each scan. The sampled data derived from repetitive scans are digitized and sequentially stored and added in their respective channels of a storage unit to produce a time average for improving the signal noise ration. The pseudorandom binary sequence is synchronized with the time scan of the composite resonance signal to preserve the phase relation between successively sampled and stored data from successive scans, whereby either pure absorption or pure dispersion mode resonance data is obtained.
Inventors
- 👤 Weston A Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:10
CPC Classifications
G; G06; G06F; G06F17/00; G06F17/10; G06F17/18; G01; G01R; G01R23/00; G01R33/00; G01R33/20; G01R33/44; G01R33/46; G01R33/4616
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
203 words
In a radio frequency spectrometer, means for generating a band of radio frequency energy to be applied to a sample of matter to be analyzed, such energy having a sufficient bandwidth to cover the spectral lines of the sample to be analyzed for simultaneously exciting radio frequency resonance of different resonance spectral lines within the sample, means for detecting the excited resonance of the sample to obtain a composite resonance signal therefrom for analysis of the sample, means for repetitively time scanning and storing a multiplicity of successive time displaced components of the composite resonant signal in a multiplicity of respective channels, means for reading out the signal components stored in such channels, the improvement wherein, said means for generating the band of radio frequency energy to be applied to the sample includes; means for generating a radio frequency carrier signal, means for generating a pseudorandom sequence of outputs, means for modulating the carrier signal with the pseudorandom output sequence; and means for synchronizing the storage of the successive time displaced resonance components in the respective channels with the pseudorandom output sequence for maintaining phase of the resonance components stored in a given channel on successive time scans of the composite resonance signal.
Claim 2
Dependent Claim
203 words
In a radio frequency spectrometer, means for generating a band of radio frequency energy to be applied to a sample of matter to be analyzed, such energy having a sufficient bandwidth to cover the spectral lines of the sample to be analyzed for simultaneously exciting radio frequency resonance of different resonance spectral lines within the sample, means for detecting the excited resonance of the sample to obtain a composite resonance signal therefrom for analysis of the sample, means for repetitively time scanning and storing a multiplicity of successive time displaced components of the composite resonant signal in a multiplicity of respective channels, means for reading out the signal components stored in such channels, the improvement wherein, said means for generating the band of radio frequency energy to be applied to the sample includes; means for generating a radio frequency carrier signal, means for generating a pseudorandom sequence of outputs, means for modulating the carrier signal with the pseudorandom output sequence; and means for synchronizing the storage of the successive time displaced resonance components in the respective channels with the pseudorandom output sequence for maintaining phase of the resonance components stored in a given channel on successive time scans of the composite resonance signal.
Claim 3
Dependent Claim
16 words
The apparatus of claim 1 wherein the pseudorandom sequence is a sequence of binary data outputs.
Claim 4
Dependent Claim
41 words
The apparatus of claim 2 wherein said means for modulating the carrier signal with the pseudorandom binary sequence includes a phase modulator for modulating the phase of the carrier signal by 180* relative phase in accordance with the binary pseudorandom sequence.
Claim 5
Dependent Claim
53 words
The apparatus of claim 2 wherein said means for generating a pseudorandom binary sequence includes a shift register having an array of binary elements, means forming an electrical feedback circuit loop containing at least one Modulo-2-Adder interconnecting the ends of said binary array, said shift register being connected for a maximum length sequence.
Claim 6
Dependent Claim
16 words
The apparatus of claim 1 wherein the radio frequency spectrometer is a nuclear magnetic resonance spectrometer.
Claim 7
Dependent Claim
16 words
The apparatus of claim 1 wherein the radio frequency spectrometer is a nuclear quadrupole resonance spectrometer.
Claim 8
Dependent Claim
16 words
The apparatus of claim 1 wherein the radio frequency spectrometer is an electron spin resonance spectrometer.
Claim 9
Dependent Claim
14 words
The apparatus of claim 1 wherein the radio frequency spectrometer is a microwave spectrometer.
Claim 10
Dependent Claim
103 words
The apparatus of claim 2 wherein said means for storing time displaced components of the composite resonance signal in respective channels includes, means forming an analog-to-digital converter for sequentially sampling the amplitude of each composite resonance signal at certain time displaced intervals, and for converting the sampled amplitude components into a sequence of binary digital resonance output data, means for addressing the sequence of binary digital resonance data outputs to different respective channels for storage therein, and wherein said synchronizing means synchronizes the sampling of the resonance signal by said analog-to-digital converter with the binary data sequence applied to said carrier frequency modulator.
Claim 11
Dependent Claim
51 words
The apparatus of claim 9 wherein said analog-to-digital converter includes means for repetitively time scanning the composite resonance signal and wherein said synchronizing means synchronizes the start of each time scan of the composite resonance signal with the start of each pseudorandom binary data sequence as applied to said modulator means.
Claim 12
Dependent Claim
66 words
The apparatus of claim 10 wherein said channel read-out means includes means for sequentially reading out the cumulative digital data in each channel as derived from a multiplicity of time scans of the resonance signal, and means for Fourier transforming the successive readouts from different channels to derive a sequence of outputs representative of a time average of the different spectral lines of the resonant signal.
References Cited (Backward Citations)
US3416381A
Cited
US3475680A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |