US5821825A
Expired / Lapsed
US
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Optically controlled oscillator
Assignee: Northrop Grumman Systems Corp
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Filing: 1996-11-26
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Granted: 1998-10-13
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Expires: 2016-11-26
Abstract
Abstract An optically controlled oscillator utilizes a HEMT or a PIN diode as a photodetector and either a HEMT or HBT as an active inductor. The optically controlled HEMT active inductor provides a means for tuning the frequency of the oscillator. The optical receiver includes an optically tunable active inductor using a photodetector which includes a resonant tank circuit of an electronic oscillator to allow both optical/digital quench and unquench of an oscillator or digital AM detection with an improved signal to noise ratio, or optical FM modulation and analog AM detection by tuning/shifting the frequency of the oscillation through the detection of the optical light intensity.
Inventors
- 👤 Kevin W. Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:26
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/18; H03B5/1841; H03B5/1847; H03B5/1852; H03D; H03D9/00
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
45 words
An optically controlled oscillator comprising: a heterojunction bipolar transistor (HBT) having base, collector and emitter terminals; and an active inductor tank circuit electrically coupled to said HBT, including a high electron mobility transistor (HEMT) and a photodetector and an optical port for exciting said photodetector.
Claim 2
Dependent Claim
45 words
An optically controlled oscillator comprising: a heterojunction bipolar transistor (HBT) having base, collector and emitter terminals; and an active inductor tank circuit electrically coupled to said HBT, including a high electron mobility transistor (HEMT) and a photodetector and an optical port for exciting said photodetector.
Claim 3
Dependent Claim
17 words
The optically controlled oscillator as recited in claim 1, wherein said photodetector is formed from an HEMT.
Claim 4
Dependent Claim
18 words
The optically controlled oscillator as recited in claim 1, wherein said photodetector is formed from a PIN diode.
Claim 5
Dependent Claim
19 words
The optically controlled oscillator as recited in claim 1, wherein said HBT is connected in a common collector configuration.
Claim 6
Dependent Claim
22 words
The optically controlled oscillator as recited in claim 1, wherein said oscillator includes a bias current source and an output coupling capacitor.
Claim 7
Dependent Claim
27 words
The optically controlled oscillator as recited in claim 1, wherein said active inductor tank circuit includes one or more tuning ports for externally adjusting the oscillation frequency.
Claim 8
Dependent Claim
30 words
The optically controlled oscillator as recited in claim 1, wherein said active inductor tank circuit includes a first DC tuning port for adjusting the quiescent bias of said active inductor.
Claim 9
Dependent Claim
28 words
The optically controlled oscillator as recited in claim 1, wherein said active inductor tank circuit includes a second DC tuning port for adjusting the bias of the photodetector.
Claim 10
Dependent Claim
20 words
The optically controlled oscillator as recited in claim 5, wherein said bias current source is formed as a current mirror.
Claim 11
Dependent Claim
23 words
The optically controlled oscillator as recited in claim 5, wherein said active inductor tank circuit is formed from two HEMTs connected in cascode.
Claim 12
Dependent Claim
19 words
The optically controlled oscillator as recited in claim 1, wherein said oscillator is formed as a monolithically integrated device.
Claim 13
Dependent Claim
57 words
An optical receiver comprising: a heterojunction bipolar transistor (HBT) having base, collector and emitter terminals and a common source high electron mobility transistor (HEMT), connected in cascode; and an active inductor tank circuit coupled to the base of said HBT, said tank circuit including an HEMT and a photodetector and an optical port for exciting said photodetector.
Claim 14
Dependent Claim
57 words
An optical receiver comprising: a heterojunction bipolar transistor (HBT) having base, collector and emitter terminals and a common source high electron mobility transistor (HEMT), connected in cascode; and an active inductor tank circuit coupled to the base of said HBT, said tank circuit including an HEMT and a photodetector and an optical port for exciting said photodetector.
Claim 15
Dependent Claim
16 words
The optical receiver as recited in claim 12, wherein said photodetector is formed as an HEMT.
Claim 16
Dependent Claim
17 words
The optical receiver as recited in claim 12, wherein said photodetector is formed as an PIN diode.
Claim 17
Dependent Claim
30 words
The optically controlled oscillator as recited in claim 12, wherein said active inductor tank circuit includes a first DC tuning port for adjusting the quiescent bias of said active inductor.
Claim 18
Dependent Claim
28 words
The optically controlled oscillator as recited in claim 12, wherein said active inductor tank circuit includes a second DC tuning port for adjusting the bias of the photodetector.
References Cited (Backward Citations)
US5347235A
Cited
US5623233A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-10-12 | 2002-04-13 | 2002-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-12 | 2006-04-13 | 2006-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-12 | 2010-04-13 | 2010-10-13 | $7700.00 | Window Closed / Lapsed |