Patent US3911433A successfully refreshed from Google Patents.
US3911433A
Expired / Lapsed
US
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Infrared microwave transponder
Assignee: United States Department of the Army
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Filing: 1974-07-12
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Granted: 1975-10-07
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Expires: 1994-07-12
Abstract
Abstract An infrared microwave transponder comprising antenna means for receiving through an infrared microwave lens an infrared signal which includes a microwave signal representative of radar reflections, means for demodulating the infrared signal and generating a microwave signal representative of the radar reflections, means for attenuating the microwave signal in inverse proportion to the magnitude of the infrared signal, and means for directing the attenuated microwave signal to the antenna means to cause radiation of the attenuated microwave signal through the infrared microwave lens.
Inventors
- 👤 Charles M Redman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:35
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/11; G; G01; G01S; G01S7/00; G01S7/02; G01S7/40; G01S7/4052; G01S7/4082
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
83 words
An infrared microwave transponder comprising: antenna means for receiving through an infrared microwave lens an infrared signal which includes a microwave signal representative of radar reflections, means for demodulating said infrared signal and generating a microwave signal representative of said radar reflections, means for attenuating said microwave signal in inverse proportion to the magnitude of said infrared signal, and means for directing an attenuated microwave signal to said antenna means to cause radiation of said attenuated microwave signal through said infrared microwave lens.
Claim 2
Dependent Claim
83 words
An infrared microwave transponder comprising: antenna means for receiving through an infrared microwave lens an infrared signal which includes a microwave signal representative of radar reflections, means for demodulating said infrared signal and generating a microwave signal representative of said radar reflections, means for attenuating said microwave signal in inverse proportion to the magnitude of said infrared signal, and means for directing an attenuated microwave signal to said antenna means to cause radiation of said attenuated microwave signal through said infrared microwave lens.
Claim 3
Dependent Claim
28 words
An infrared microwave transponder in accordance with claim 1, further comprising: a first diode for demodulating said infrared signal, and a second diode for attentuating said microwave signal.
Claim 4
Dependent Claim
25 words
An infrared microwave transponder in accordance with claim 2, wherein the impedance of said second diode varies inversely as the current through said second diode.
Claim 5
Dependent Claim
96 words
An infrared microwave transponder in accordance with claim 2, further comprising: a second antenna, a first transistor, a second transistor, a third transistor, a capacitor, means connecting said second antenna to said second transistor and to said capacitor, means connecting said first transistor to said capicitor, means connecting said second transistor to said third transistor, means connecting said third transistor to said second diode, whereby receipt of said infrared signal by said second antenna causes a decrease in current from said third transistor through said second diode causing an increase in impedance of said second diode.
Claim 6
Dependent Claim
32 words
An infrared microwave transponder in accordance with claim 4 wherein said first transistor is a phototransistor and wherein said capacitor is discharged by applying an optical recycle signal to said first transistor.
Claim 7
Dependent Claim
17 words
An infrared microwave transponder in accordance with claim 5 wherein said first diode is a PIN diode.
Claim 8
Dependent Claim
17 words
An infrared microwave transponder in accordance with claim 6 wherein said second diode is a PIN diode.
Claim 9
Dependent Claim
18 words
An infrared microwave transponder in accordance with claim 7 wherein said antenna means is a broadband spiral antenna.
Claim 10
Dependent Claim
18 words
An infrared microwave transponder in accordance with claim 8 wherein said infrared microwave lens is constructed of plastic.
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) | 1978-10-06 | 1979-04-07 | 1979-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-06 | 1983-04-07 | 1983-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-06 | 1987-04-07 | 1987-10-07 | $7700.00 | Window Closed / Lapsed |