Patent US3891934A successfully refreshed from Google Patents.
US3891934A
Expired / Lapsed
US
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Transistor amplifier with impedance matching transformer
Assignee: ADAMS-RUSSELL ELECTRONICS Co Inc 1380 MAIN ST WALTHAM MA 02154 ("A-R") A CORP OF
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Filing: 1974-05-22
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Granted: 1975-06-24
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Expires: 1994-05-22
Abstract
Abstract An amplifier includes a transistor and transformer having a primary winding and a tapped secondary winding. The primary winding is connected in series between the input terminal and the transistor emitter. The transistor base and one end of the secondary winding is grounded. The other end of the secondary winding is connected to the transistor collector. The transformer secondary tap is connected to an output terminal. The ratio of that portion of the secondary turns connected between the tap and r-f ground and the primary turns is m. The ratio of that portion of the secondary turns connected between the tap and the transistor collector and the primary turns is n. For two-way impedance match between a source resistance Rs and a load resistance RL, n m2 (Rs/RL)-m-1.
Inventors
- 👤 David E Norton
- 👤 Allen F Podell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:04
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/56; H03F1/565
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
104 words
Amplifying apparatus comprising, amplifying means having at least control, input and output electrodes, a common terminal, transformer means having at least a primary and a secondary winding, said secondary winding having a tap intermediate to first and second portions thereof, an input terminal, an output terminal, means for coupling said output terminal to said tap, meanS for coupling said primary winding between said input terminal and said input electrode, said first portion being coupled between said tap and said common terminal, said second portion being coupled between said tap and said output electrode, and means for coupling said control electrode to said common terminal.
Claim 2
Dependent Claim
104 words
Amplifying apparatus comprising, amplifying means having at least control, input and output electrodes, a common terminal, transformer means having at least a primary and a secondary winding, said secondary winding having a tap intermediate to first and second portions thereof, an input terminal, an output terminal, means for coupling said output terminal to said tap, meanS for coupling said primary winding between said input terminal and said input electrode, said first portion being coupled between said tap and said common terminal, said second portion being coupled between said tap and said output electrode, and means for coupling said control electrode to said common terminal.
Claim 3
Dependent Claim
51 words
Amplifying apparatus in accordance with claim 1 wherein the turns ratio between said first portion and said primary winding is m and between said second portion and said primary winding is n with n m2 Rs/RL -m-1 wherein Rs is a predetermined source resistance and RL is a predetermined load resistance.
Claim 4
Dependent Claim
35 words
Amplifying apparatus in accordance with claim 2 and further comprising said source resistance coupled between said input terminal and said common terminal and said load resistance coupled between said output terminal and said common terminal.
Claim 5
Dependent Claim
28 words
Amplifying apparatus in accordance with claim 1 wherein said amplifying means comprises a transistor and said control, input and output electrodes comprise base, emitter and collector electrodes, respectively.
Claim 6
Dependent Claim
34 words
Amplifying apparatus in accordance with claim 4 and further comprising, a source of d-c operating potential connected to said collector electrode through said secondary winding, and means for biasing said base and emitter electrodes.
Claim 7
Dependent Claim
78 words
Amplifying apparatus in accordance with claim 5 wherein the means for biasing said base electrode comprises a first resistor connected between said source of d-c potential and said base electrode and a second resistor connected between said base electrode and said common terminal and the means for coupling said base electrode to said common terminal comprises an r-f bypass capacitor and further comprising, another r-f bypass capacitor coupling said source of a d-c potential to said common terminal.
Claim 8
Dependent Claim
34 words
Amplifying apparatus in accordance with claim 6 wherein said means for biasing said emitter electrode comprises an emitter biasing resistor in series with an r-f choke between said common terminal and said primary winding.
Claim 9
Dependent Claim
40 words
Amplifying apparatus in accordance with claim 7 wherein said means for coupling said primary winding between said input terminal and said emitter electrode comprises a capacitor and said means for coupling said output terminal to said tap comprises a capacitor.
References Cited (Backward Citations)
US2701281A
Cited
US2691077A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-23 | 1978-12-23 | 1979-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-23 | 1982-12-23 | 1983-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-23 | 1986-12-23 | 1987-06-24 | $7700.00 | Window Closed / Lapsed |