Patent US3757330A successfully refreshed from Google Patents.
US3757330A
Expired / Lapsed
US
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Microwave interferometers
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1971-11-29
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Granted: 1973-09-04
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Expires: 1991-11-29
Abstract
Abstract This invention involves an interferometer arranged to measure the distance to a movable object. The interferometer includes a main wave guide for radiating electromagnetic waves towards the object and for receiving the electromagnetic wave after reflection from the object, and a secondary wave guide system, including detectors coupled to the main wave guide in order to receive components of both the radiated and reflected waves. By appropriate positioning of the coupling between main and secondary wave guides, detectors in the secondary wave guide system can readily determine the distance of an object.
Inventors
- 👤 E Hotston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:47
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/06; G01S13/08; G01S13/32; G01S13/36
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
166 words
A micro-wave interferometer, comprising a main wave guide, generating means for successively propagating along the main wave guide electromagnetic wave having frequencies respectively equal to f and Delta f for reflection back from a movable object, first and second side wave guides, first and second couplings non-reflectively and weakly coupling the first and second wave guides to the main wave guide at spaced positions therealong to receive energy from the resulting standing wave patterns set up in the main wave guide, and first and second detectors respectively connected to the two side wave guides to measure the respective amplitudes Ay and Ax of the waves coupled into the side wave guides when the electromagnetic wave has the frequency f, and to measure the respective amplitudes Ay + Delta Ay and Ax + Delta Ax of the waves in the two side wave guides when the electromagnetic wave has the frequency f + Delta f, whereby to enable the distance d to be determined from the formula
Claim 2
Dependent Claim
166 words
A micro-wave interferometer, comprising a main wave guide, generating means for successively propagating along the main wave guide electromagnetic wave having frequencies respectively equal to f and Delta f for reflection back from a movable object, first and second side wave guides, first and second couplings non-reflectively and weakly coupling the first and second wave guides to the main wave guide at spaced positions therealong to receive energy from the resulting standing wave patterns set up in the main wave guide, and first and second detectors respectively connected to the two side wave guides to measure the respective amplitudes Ay and Ax of the waves coupled into the side wave guides when the electromagnetic wave has the frequency f, and to measure the respective amplitudes Ay + Delta Ay and Ax + Delta Ax of the waves in the two side wave guides when the electromagnetic wave has the frequency f + Delta f, whereby to enable the distance d to be determined from the formula
Claim 3
Dependent Claim
24 words
An interferometer according to claim 1, wherein the main wave guide includes a phase shifter mounted therein to vary the sensitivity of the interferometer.
Claim 4
Dependent Claim
19 words
An inteferometer according to claim 1, wherein the main wave guide and the side wave guides comprise coaxial lines.
Claim 5
Dependent Claim
26 words
An interferometer according to claim 1, wherein the main wave guide is open-ended and arranged to transmit and receive electromagnetic waves to and from the reflector.
Claim 6
Dependent Claim
15 words
An interferometer according to claim 1, wherein the reflector is inside the main wave guide.
Claim 7
Dependent Claim
56 words
An interferometer according to claim 1, wherein the first and second side wave guides are mechanically dissimilar, the distance along the main wave guide between the two side wave guides being (n - 1) pi g/2 where n is an integer and pi g is the wavelength of the propagating wave in the main wave guide.
Claim 8
Dependent Claim
51 words
Apparatus according to claim 5, wherein the two side wave guides are positioned at the same distance along the length of the main wave guide whereby the two side wave guides respectively provide outputs proportional to the electric field and the magnetic field of the electromagnetic wave in the main waveguide.
Claim 9
Independent Claim
128 words
A method of measuring the distance d of an object from a predetermined point, comprising the steps of propagating an electromagnetic wave past Said predetermined point of said object, switching the frequency of the electromagnetic wave alternately between two frequencies, reflecting said electromagnetic wave from said object substantially without loss back past said predetermined point to set up a standing wave, measuring the magnitudes Ay and Ay + Delta Ay of said switched wave at said predetermined point, measuring the magnitudes Ax and Ax + Delta Ax of said switched wave at a further point such that the phase difference between the two sets of measured signals is an odd number of pi radians, and determining the distance of the object from the predetermined point from the formula
Claim 10
Independent Claim
128 words
A method of measuring the distance d of an object from a predetermined point, comprising the steps of propagating an electromagnetic wave past Said predetermined point of said object, switching the frequency of the electromagnetic wave alternately between two frequencies, reflecting said electromagnetic wave from said object substantially without loss back past said predetermined point to set up a standing wave, measuring the magnitudes Ay and Ay + Delta Ay of said switched wave at said predetermined point, measuring the magnitudes Ax and Ax + Delta Ax of said switched wave at a further point such that the phase difference between the two sets of measured signals is an odd number of pi radians, and determining the distance of the object from the predetermined point from the formula
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |