Patent US3609520A successfully refreshed from Google Patents.
US3609520A
Expired / Lapsed
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Bimodel cavity resonator for microwave spectrometers
Assignee: Varian Medical Systems Inc
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Filing: 1970-02-04
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Granted: 1971-09-28
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Expires: 1990-02-04
Abstract
Abstract A microwave spectrometer employing a bimodal cavity resonator for electron spin resonance experiments is disclosed. The bimodal cavity includes a shared region of space and an adjacent unshared region of space, such shared region being arranged to support two spatially orthogonal modes of oscillation and the unshared region of space being arranged to support the fields of only one of the modes of oscillation to the exclusion of the other. A set of conductive rods are disposed at the boundary of the adjacent shared and unshared regions, the rods being generally parallel to the magnetic field vector of the mode of oscillation which is common to both the shared and unshared regions and being generally perpendicular to the magnetic field vector of the mode which is to be excluded from the unshared region, whereby spatial orthogonality and positioning of the magnetic field of the two modes within the shared sample volume is enhanced.
Inventors
- 👤 Robert C Sneed Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:52
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/34; G01R33/345; H; H01; H01P; H01P7/00; H01P7/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
233 words
In a microwave spectrometer, bimodal cavity resonator means for supporting first and second spatially orthogonal resonant modes of oscillation therein, said bimodal cavity resonator including a shared region to be partially occupied by a volume of sample material under investigation and such shared region being a regioN of space shared by fields of both the first and second resonant modes of oscillation, said cavity also including an unshared region of space adjacent said shared region and containing fields of only the first resonant mode of oscillation to the exclusion of the fields of the second resonant mode of oscillation, THE IMPROVEMENT COMPRISING, a set of conductor means extending across said cavity from one wall thereof to an opposed wall thereof at the boundary of said adjacent shared and unshared regions of said bimodal cavity, and said set of conductor means being elongated and disposed generally parallel to each other with their direction of elongation being generally parallel to the magnetic field vector of said first resonant mode in the unshared region of said cavity and generally perpendicular to the magnetic field vector of said second resonant mode for preventing substantial bulging of the magnetic field of the second resonant mode into the unshared portion of said cavity resonator, whereby improved spatial orthogonality and improved positioning of the magnetic field of said first and second resonant modes within the shared sample volume is obtained.
Claim 2
Dependent Claim
233 words
In a microwave spectrometer, bimodal cavity resonator means for supporting first and second spatially orthogonal resonant modes of oscillation therein, said bimodal cavity resonator including a shared region to be partially occupied by a volume of sample material under investigation and such shared region being a regioN of space shared by fields of both the first and second resonant modes of oscillation, said cavity also including an unshared region of space adjacent said shared region and containing fields of only the first resonant mode of oscillation to the exclusion of the fields of the second resonant mode of oscillation, THE IMPROVEMENT COMPRISING, a set of conductor means extending across said cavity from one wall thereof to an opposed wall thereof at the boundary of said adjacent shared and unshared regions of said bimodal cavity, and said set of conductor means being elongated and disposed generally parallel to each other with their direction of elongation being generally parallel to the magnetic field vector of said first resonant mode in the unshared region of said cavity and generally perpendicular to the magnetic field vector of said second resonant mode for preventing substantial bulging of the magnetic field of the second resonant mode into the unshared portion of said cavity resonator, whereby improved spatial orthogonality and improved positioning of the magnetic field of said first and second resonant modes within the shared sample volume is obtained.
Claim 3
Dependent Claim
17 words
The apparatus of claim 1 wherein said set of conductor means comprises a plurality of conductive rods.
Claim 4
Dependent Claim
103 words
The apparatus of claim 1 wherein said bimodal cavity resonator comprises first and second intersecting rectangular waveguide structures, each of said waveguide structures being shorted at the ends, said rectangular waveguide structures each including a pair of broad walls interconnected by a pair of narrow sidewalls and being disposed intersecting at substantially right angles with the broad walls of said first waveguide structure being disposed substantially parallel to the longitudinal axis of said second waveguide structure and with the plane of said broad walls of said first waveguide structure being perpendicular to the plane of the broad walls of said second waveguide structure.
Claim 5
Dependent Claim
150 words
The apparatus of claim 3 wherein each of said first and second waveguide structures includes portions extending on opposite sides of the other waveguide structure in the general composite configuration of a cross, and wherein there are first and second sets of said conductor means orthogonally oriented with respect to each other with said first set of conductor means extending across the mouths of said first waveguide at the intersection thereof with said second waveguide, said first set of conductors extending parallel to the broad walls of said first waveguide, and said second set of conductor means extending across said second waveguide structure from one narrow wall thereof to the opposed narrow wall, said second set of conductors being disposed substantially in the planes of the narrow walls of said first waveguide structure, and said second conductor means extending generally parallel to the broad walls of said second waveguide structure.
Claim 6
Dependent Claim
41 words
The apparatus of claim 4 wherein said first and second waveguide structures are dimensioned for resonance in the TE102 mode for said first and second resonant modes of oscillation, respectively, of said bimodal cavity at the operating frequency of the spectrometer.
Claim 7
Dependent Claim
103 words
The apparatus of claim 4 wherein each of said waveguide structures which extends on the opposite side of the other waveguide structure is separated by a slot passing through the broad walls of said waveguide structures in a plane parallel to the narrow walls of the respective waveguide structure and passing through the center line of the respective waveguide structure, and means for applying a time varying magnetic field to the outside of said bimodal cavity, whereby said slots serve to inhibit eddy currents which would otherwise tend to shield the sample region of said cavity from the applied time varying magnetic field.
Claim 8
Dependent Claim
103 words
The apparatus of claim 4 including a tuning means movable in each of a pair of unshared regions of said first waveguide structure for tuning the resonant frequency of the first resonAnt mode of oscillation of said bimodal cavity, and means for ganging the movement of said tuning means such that the magnetic fields of said first resonant mode are perturbed by said tuning means in a symmetrical manner with respect to the center of said first waveguide structure, whereby tuning of said first resonant mode does not disturb symmetry of the magnetic field of said first resonant mode within the sample volume.
Claim 9
Dependent Claim
50 words
The apparatus of claim 7 wherein said second waveguide structure includes an optically transparent end wall in an unshared region thereof facing the sample region for transmission of optical radiation therethrough along an unobstructed straight line path which intersects the sample volume within the shared region of said bimodal cavity.
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) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |