US3643181A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amplitude and/or frequency-modulated paramagnetic resonance oscillator
Assignee: United States Department of the Army
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Filing: 1970-06-11
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Granted: 1972-02-15
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Expires: 1990-06-11
Abstract
Abstract This oscillator includes a pair of radiofrequency (RF) coils orthogonally disposed to each other and coupled to a magnetized paramagnetic sample. At paramagnetic resonance, the two coils are effectively coupled and a feedback path is completed through one or more amplifiers which connect the two RF-coils. The oscillator can be both frequency- and amplitude-modulated.
Inventors
- 👤 William A Stirrat
- 👤 William L Rollwitz
- 👤 Gilbert A Persyn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:31
CPC Classifications
H; H03; H03C; H03C5/00; H03C7/00; H03C7/02; H03L; H03L7/00; H03L7/26
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
132 words
An oscillator which includes a paramagnetic material as the major frequency-determining element, comprising, a pair of radiofrequency coils coupled to said material, magnetically orthogonal to each other and mutually decoupled from each other, means to produce a direct magnetic field within said material along an axis orthogonal to both said radiofrequency coils, a third coil disposed along said axis for producing a magnetic field that is coupled to said material and is superposed on said direct magnetic field, a frequency-modulation source connected to said third coil for energizing said third coil to produce its magnetic field whereby said direct magnetic field pulsates in accordance with the output of said frequency-modulation source to frequency-modulate said oscillator, and a feedback loop connected between said radiofrequency coils, said feedback loop comprising at least one amplifier.
Claim 2
Dependent Claim
132 words
An oscillator which includes a paramagnetic material as the major frequency-determining element, comprising, a pair of radiofrequency coils coupled to said material, magnetically orthogonal to each other and mutually decoupled from each other, means to produce a direct magnetic field within said material along an axis orthogonal to both said radiofrequency coils, a third coil disposed along said axis for producing a magnetic field that is coupled to said material and is superposed on said direct magnetic field, a frequency-modulation source connected to said third coil for energizing said third coil to produce its magnetic field whereby said direct magnetic field pulsates in accordance with the output of said frequency-modulation source to frequency-modulate said oscillator, and a feedback loop connected between said radiofrequency coils, said feedback loop comprising at least one amplifier.
Claim 3
Dependent Claim
68 words
The oscillator of claim 1 wherein said feedback loop comprises a video amplifier and a variable phase shifter, and an automatic level control circuit, the input of said level control circuit being the output of said video amplifier, the output of said level control circuit being applied to said video amplifier as a gain control signal; and means to superimpose an amplitude-modulating voltage on said gain control signal.
Claim 4
Dependent Claim
37 words
The oscillator of claim 2 further including a variable capacitor connected in parallel with one of said radiofrequency coils, said coil and capacitor being tuned to a passband which includes the resonant frequency of said paramagnetic material.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-14 | 1975-08-16 | 1976-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-14 | 1979-08-16 | 1980-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-14 | 1983-08-16 | 1984-02-15 | $7700.00 | Window Closed / Lapsed |