US4431965A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave radiation monitor
Assignee: Lockheed Martin Corp
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Filing: 1981-04-16
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Granted: 1984-02-14
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Expires: 2001-04-16
Abstract
Abstract This portable microwave radiation monitor utilizes an antenna formed in a dual Archimedean spiral. The power density of the electric field is indicated on a meter coupled to diode means connected across the inner terminals of the antenna by inductance means selected to resonate with the variable capacitance of the diode, substantially at the frequency of the field being monitored.
Inventors
- 👤 Edward E. Aslan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:36
CPC Classifications
G; G01; G01R; G01R21/00; G01R21/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
71 words
A microwave radiation monitor comprising: a dual Archimedean spiral antenna; a diode characterized by a variable capacitance that decreases as the reverse voltage across said diode increases; inductance means coupling said diode to the inner ends of said spiral antenna, the reactance of said inductance means being selected to substantially resonate with said capacitance when a predetermined frequency is monitored; and a meter connected to measure the current through said diode.
Claim 2
Dependent Claim
71 words
A microwave radiation monitor comprising: a dual Archimedean spiral antenna; a diode characterized by a variable capacitance that decreases as the reverse voltage across said diode increases; inductance means coupling said diode to the inner ends of said spiral antenna, the reactance of said inductance means being selected to substantially resonate with said capacitance when a predetermined frequency is monitored; and a meter connected to measure the current through said diode.
Claim 3
Dependent Claim
22 words
A microwave radiation monitor as defined in claim 1, wherein said inductance means is a short section of parallel wire transmission line.
Claim 4
Dependent Claim
21 words
A microwave radiation monitor as defined in claim 2 wherein said meter is connected to said diode by high resistance leads.
Claim 5
Dependent Claim
24 words
A microwave radiation monitor as defined in claim 3, wherein said high resistance leads are tapered with the narrow end connected to said diode.
Claim 6
Dependent Claim
55 words
A microwave radiation monitor as defined in claim 3, including spaced contacts along one of said high resistance leads, and means to connect a properly polarized dc voltage between said contacts to create current flow through said diode, whereby said meter indicates at least a predetermined current level when the components are in working order.
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) | 1987-02-13 | 1987-08-15 | 1988-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-13 | 1991-08-15 | 1992-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-13 | 1995-08-15 | 1996-02-14 | $7700.00 | Window Closed / Lapsed |