Patent US5532650A successfully refreshed from Google Patents.
US5532650A
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US
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High-frequency amplifier
Assignee: Alps Alpine Co Ltd
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Filing: 1995-01-19
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Granted: 1996-07-02
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Expires: 2015-01-19
Abstract
Abstract A high-frequency amplifier has a first signal amplifier which includes a field effect transistor, and a constant-current circuit which is direct current connected, as well as cascade-connected, to the field effect transistor for maintaining a constant drain current of the field effect transistor. This constant-current circuit also acts as a second amplifier. The constant-current circuit may comprise a bipolar transistor or temperature compensation circuit. In this high-frequency amplifier, its gain and noise figure are stable against ambient temperature changes and power consumption efficiency is improved. This high-frequency amplifier is also suitable for mass production.
Inventors
- 👤 Sadao Igarashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:49
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/30; H03F1/306; H03F3/00; H03F3/189; H03F3/19; H03F3/193; H03F3/1935; H03F2200/00; H03F2200/372
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
69 words
A high-frequency amplifier, comprising: a first signal amplifier including a field effect transistor; and a constant-current circuit which is cascade-connected to said field effect transistor such that a constant drain current flows through said field effect transistor, said constant-current circuit also being connected to the field effect transistor such that the constant-current circuit acts as a second signal amplifier for amplifying a signal output from said first signal amplifier.
Claim 2
Dependent Claim
69 words
A high-frequency amplifier, comprising: a first signal amplifier including a field effect transistor; and a constant-current circuit which is cascade-connected to said field effect transistor such that a constant drain current flows through said field effect transistor, said constant-current circuit also being connected to the field effect transistor such that the constant-current circuit acts as a second signal amplifier for amplifying a signal output from said first signal amplifier.
Claim 3
Dependent Claim
21 words
A high-frequency amplifier according to claim 1, wherein said constant-current circuit is connected to the source of said field effect transistor.
Claim 4
Dependent Claim
66 words
A high-frequency amplifier according to claim 1, wherein said constant-current circuit comprises a bipolar transistor having a base connected to a drain of the field effect transistor, a collector connected to a source of the field effect transistor, and an emitter connected to a reference voltage such that a drain current through the field effect transistor is equal to a collector current through the bipolar transistor.
Claim 5
Dependent Claim
16 words
A high-frequency amplifier according to claim 1, wherein said constant-current circuit comprises a temperature compensation circuit.
Claim 6
Dependent Claim
15 words
A high-frequency amplifier according to claim 4, wherein said temperature compensation circuit includes a diode.
Claim 7
Dependent Claim
106 words
A high-frequency amplifier, comprising: a first signal amplifier including a field effect transistor having a first terminal connected to a first voltage source through an impedance element, the field effect transistor also having a second terminal; and a constant-current circuit cascade-connected to the first signal amplifier, the constant-current source including a bipolar transistor having a base connected to the first terminal of the field effect transistor, a collector connected to the second terminal of the field effect transistor, and an emitter connected to a second voltage source; wherein a drain current through the field effect transistor is equal to a collector current through the bipolar transistor.
Claim 8
Dependent Claim
106 words
A high-frequency amplifier, comprising: a first signal amplifier including a field effect transistor having a first terminal connected to a first voltage source through an impedance element, the field effect transistor also having a second terminal; and a constant-current circuit cascade-connected to the first signal amplifier, the constant-current source including a bipolar transistor having a base connected to the first terminal of the field effect transistor, a collector connected to the second terminal of the field effect transistor, and an emitter connected to a second voltage source; wherein a drain current through the field effect transistor is equal to a collector current through the bipolar transistor.
Claim 9
Dependent Claim
52 words
The high-frequency amplifier according to claim 6, wherein the constant-current circuit further comprises a first resistor connected between the first voltage source and the base of the bipolar transistor, a diode connected to the base of the bipolar transistor, and a second resistor connected between the diode and the second voltage source.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-07-02 | 2000-01-01 | 2000-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-07-02 | 2004-01-01 | 2004-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-07-02 | 2008-01-01 | 2008-07-02 | $7700.00 | Window Closed / Lapsed |