US3913012A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave moisture measuring system with reflection suppressing means
Assignee: Frieseke and Hoepfner GmbH
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Filing: 1974-02-22
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Granted: 1975-10-14
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Expires: 1994-02-22
Abstract
Abstract The microwave absorbtivity of a workpiece, which is proportional to the moisture content thereof, is measured by transmitting a beam of microwave radiation from a sending (radiating or transmitting) antenna on one side of the workpiece at a right angle through the workpiece to a receiving antenna on the other side of the workpiece. This beam is received at the other side of the workpiece and an output is generated which corresponds to the intensity of radiation received. Radiation reflected by the workpiece back into the sending antenna (backscatter) is detected at the sending antenna and another output is generated which corresponds to the intensity of microwave radiation reflected back into this antenna. The reflection of microwave radiation from either antenna to the other antenna and any internal reflection of microwave radiation in the transmitting antenna are suppressed in this system so as to eliminate standing waves.
Inventors
- 👤 Klaus Kujath
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:39
CPC Classifications
G; G01; G01N; G01N22/00; G01N22/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
135 words
A method of measuring the microwave absorptivity of a flat workpiece comprising the steps of: transmitting a beam of microwave radiation from a sending antenna on one side of said workpiece at a right angle through said workpiece to a receiving antenna on the other side thereof; receiving said beam at said receiving antenna and generating an output corresponding to the intensity of microwave radiation received; detecting through said sending antenna microwave radiation reflected by said workpiece back from said beam and generating an output corresponding to the intensity of reflected microwave radiation detected; suppressing the reflection of microwave radiation from each of said antennas to the other antenna and internal reflections of microwave radiation in said sending antenna; and combining said outputs for determination of the portion of microwave energy absorbed by said workpiece.
Claim 2
Independent Claim
135 words
A method of measuring the microwave absorptivity of a flat workpiece comprising the steps of: transmitting a beam of microwave radiation from a sending antenna on one side of said workpiece at a right angle through said workpiece to a receiving antenna on the other side thereof; receiving said beam at said receiving antenna and generating an output corresponding to the intensity of microwave radiation received; detecting through said sending antenna microwave radiation reflected by said workpiece back from said beam and generating an output corresponding to the intensity of reflected microwave radiation detected; suppressing the reflection of microwave radiation from each of said antennas to the other antenna and internal reflections of microwave radiation in said sending antenna; and combining said outputs for determination of the portion of microwave energy absorbed by said workpiece.
Claim 3
Dependent Claim
46 words
The method defined in claim 1 wherein the reflection of microwave radiation from said receiving antenna to the sending antenna is suppressed by adjusting said receiving antenna in the absence of a workpiece between said antennas until said output corresponding to reflected radiation is substantially null.
Claim 4
Dependent Claim
37 words
The method defined in claim 1 wherein the reflection of microwave radiation from said sending antenna toward said receiving antenna is suppressed by adjusting a directional coupler on said sending antenna serving to detect said reflected radiation.
Claim 5
Dependent Claim
27 words
The method defined in claim 1 wherein the internal reflections of microwave radiation in said sending antenna are suppressed by adjusting the waveguIde for said sending antenna.
Claim 6
Independent Claim
197 words
An apparatus for measuring the microwave absorptivity of a flat workpiece, said apparatus comprising: a sending antenna on one side of said workpiece and trained at a right angle thereto; a receiving antenna on the other side of said workpiece in line with said sending antenna; means connected to said sending antenna for transmitting a beam of microwave radiation therefrom through said workpiece at a right angle thereto to said receiving antenna; means at said receiving antenna for receiving said beam and generating an output corresponding to the intensity of microwave radiation received; means at said sending antenna for detecting microwave radiation reflected back by said workpiece into said sending antenna and for generating an output corresponding to the intensity of reflected microwave radiation; means connected to said means at said antennas for combining said outputs; first means connected to said receiving antenna for suppressing the reflection of microwave radiation from said receiving antenna back to said sending antenna; second means connected to said sending antenna for suppressing the reflection of microwave radiation from said antenna back to said receiving antenna; and third means at said sending antenna for suppressing the internal reflection therein of microwave radiation.
Claim 7
Independent Claim
197 words
An apparatus for measuring the microwave absorptivity of a flat workpiece, said apparatus comprising: a sending antenna on one side of said workpiece and trained at a right angle thereto; a receiving antenna on the other side of said workpiece in line with said sending antenna; means connected to said sending antenna for transmitting a beam of microwave radiation therefrom through said workpiece at a right angle thereto to said receiving antenna; means at said receiving antenna for receiving said beam and generating an output corresponding to the intensity of microwave radiation received; means at said sending antenna for detecting microwave radiation reflected back by said workpiece into said sending antenna and for generating an output corresponding to the intensity of reflected microwave radiation; means connected to said means at said antennas for combining said outputs; first means connected to said receiving antenna for suppressing the reflection of microwave radiation from said receiving antenna back to said sending antenna; second means connected to said sending antenna for suppressing the reflection of microwave radiation from said antenna back to said receiving antenna; and third means at said sending antenna for suppressing the internal reflection therein of microwave radiation.
References Cited (Backward Citations)
US3644826A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-13 | 1979-04-14 | 1979-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-13 | 1983-04-14 | 1983-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-13 | 1987-04-14 | 1987-10-14 | $7700.00 | Window Closed / Lapsed |