US4037169A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transistor amplifier
Assignee: Sony Corp
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Filing: 1975-05-20
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Granted: 1977-07-19
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Expires: 1995-05-20
Abstract
Abstract A low-noise, small-signal transistor amplifier particularly suited for use as a preamplifier in an acoustic or audio apparatus employs a field effect transistor having triode-type characteristics in a common source type amplification circuit, with the gate of the field effect transistor being connected directly to an input terminal which receives the audio signals to be amplified, the drain of the field effect transistor being connected to an output terminal, preferably through a capacitor for DC cutting, and the source of the field effect transistor being connected to a point of reference potential, such as the ground, through a parallel circuit of a resistor and a capacitor.
Inventors
- 👤 Tadao Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:26
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/181; H03F3/183; H03F3/185; H03F3/1855; H03F2200/00; H03F2200/372
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
130 words
A transistor amplifier comprising an input terminal for receiving audio signals to be amplified, an output terminal for delivering the amplified audio signals, a field effect transistor for amplifying said audio signals and including gate, source and drain electrodes, an intrinsic semiconductor region in said field effect transistor to which one of said electrodes is connected so that a vertical channel is formed in said field effect transistor whereby its drain current does not become saturated when its drain voltage is increased so as to exhibit triode-type characteristics, means defining a reference potential, a resistor and capacitor connected in a parallel circuit between said source electrode and said reference potential, means connecting said gate electrode directly to said input terminal, and means connecting said drain electrode to said output terminal.
Claim 2
Dependent Claim
130 words
A transistor amplifier comprising an input terminal for receiving audio signals to be amplified, an output terminal for delivering the amplified audio signals, a field effect transistor for amplifying said audio signals and including gate, source and drain electrodes, an intrinsic semiconductor region in said field effect transistor to which one of said electrodes is connected so that a vertical channel is formed in said field effect transistor whereby its drain current does not become saturated when its drain voltage is increased so as to exhibit triode-type characteristics, means defining a reference potential, a resistor and capacitor connected in a parallel circuit between said source electrode and said reference potential, means connecting said gate electrode directly to said input terminal, and means connecting said drain electrode to said output terminal.
Claim 3
Dependent Claim
40 words
A transistor amplifier according to claim 1; further comprising a resistor connected between said gate electrode and said reference potential, means defining a DC source of operating voltage, and a resistor connected between said DC source and said drain electrode.
Claim 4
Dependent Claim
118 words
A transistor amplifier according to claim 1; in which said intrinsic semiconductor region is of low impurity concentration and high resistance, and wherein a semiconductor region of one type of conductivity extends over a portion of said intrinsic semiconductor region, and a semiconductor region of the opposite type of conductivity and high impurity concentration extends over said semiconductor region of said one type of conductivity and over the balance of said intrinsic semiconductor region; and in which said drain electrode is provided on said intrinsic semiconductor region, said gate electrode is provided on said semiconductor region of said one type of conductivity, and said source electrode is provided on said semiconductor region of said opposite type of conductivity.
Claim 5
Dependent Claim
58 words
A transistor amplifier according to claim 3; in which said semiconductor region of said one type of conductivity is of mesh-like configuration, and said intrinsic semiconductor region has a layer of semiconductor material of said opposite type of conductivity with a high impurity concentration at the surface of said intrinsic region on which said drain electrode is provided.
Claim 6
Dependent Claim
25 words
A transistor amplifier according to claim 1; in which said field effect transistor constitutes the sole amplifying element in a common source type amplification circuit.
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) | 1980-07-18 | 1981-01-17 | 1981-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-18 | 1985-01-17 | 1985-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-18 | 1989-01-17 | 1989-07-19 | $7700.00 | Window Closed / Lapsed |