US5023569A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable gain amplifier
Assignee: Motorola Solutions Inc
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Filing: 1989-06-29
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Granted: 1991-06-11
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Expires: 2009-06-29
Abstract
Abstract An amplification device (18) has its gain controlled by varying the current flowing into the amplification device. The current is varied (36) by a means of a variable bias network that adapts the input current in response to a control signal. In this way, the amplification device is provided with variable gain while avoiding parametric regeneration.
Inventors
- 👤 Gregory S. Raven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:51
CPC Classifications
H; H03; H03G; H03G1/00; H03G1/0005; H03G1/0035; H03G1/0082
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
59 words
An amplifier, comprising: means for variably amplifying an input signal in response to a variable bias current; bias means for providing the variable bias current to a bipolar transistor in response to a control signal; and feedback means for maintaining the variable bias current at a substantially constant level after the level has been determined by the control signal.
Claim 2
Dependent Claim
59 words
An amplifier, comprising: means for variably amplifying an input signal in response to a variable bias current; bias means for providing the variable bias current to a bipolar transistor in response to a control signal; and feedback means for maintaining the variable bias current at a substantially constant level after the level has been determined by the control signal.
Claim 3
Dependent Claim
29 words
The amplifier of claim 1, wherein said bias means comprises a resistor network having at least one resistor capable of varying its resistance in response to the control signal.
Claim 4
Dependent Claim
19 words
The amplifier of claim 1, which includes input matching means for impedance matching an input port of the amplifier.
Claim 5
Dependent Claim
19 words
The amplifier of claim 1, which includes output matching means for impedance matching an output port of the amplifier.
Claim 6
Dependent Claim
15 words
The amplifier of claim 1, wherein said feedback means comprises a transistor and a resistor.
Claim 7
Independent Claim
76 words
A method for controlling the gain of an amplifier, comprising the steps of: (a) varying a bias current to a control signal; (b) providing the variable bias current to a bipolar transistor so as to vary the gain thereof; and (c) maintaining the variable bias current at substantially the same level after the level is established by the control signal via a feedback network for offsetting a change in said level after said level is established.
Claim 8
Independent Claim
76 words
A method for controlling the gain of an amplifier, comprising the steps of: (a) varying a bias current to a control signal; (b) providing the variable bias current to a bipolar transistor so as to vary the gain thereof; and (c) maintaining the variable bias current at substantially the same level after the level is established by the control signal via a feedback network for offsetting a change in said level after said level is established.
Claim 9
Dependent Claim
97 words
An amplifier, comprising: a transistor amplifier having a base, collector, and emitter, said emitter being connected to ground for variably amplifying an input signal applied to said base in response to a variable bias current applied to said collector; a resistor network for providing said variable bias current having at least one resistor capable of varying its resistance in response to a control signal: and a feedback network coupled between said resistor network and said base for maintaining said variable bias current at a substantially constant level after a level has been determined by said control signal.
Claim 10
Dependent Claim
97 words
An amplifier, comprising: a transistor amplifier having a base, collector, and emitter, said emitter being connected to ground for variably amplifying an input signal applied to said base in response to a variable bias current applied to said collector; a resistor network for providing said variable bias current having at least one resistor capable of varying its resistance in response to a control signal: and a feedback network coupled between said resistor network and said base for maintaining said variable bias current at a substantially constant level after a level has been determined by said control signal.
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) | 1994-06-10 | 1994-12-10 | 1995-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-10 | 1998-12-10 | 1999-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-10 | 2002-12-10 | 2003-06-11 | $7700.00 | Window Closed / Lapsed |