US3895306A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-balancing push-pull amplifier
Assignee: Motorola Solutions Inc
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Filing: 1973-05-29
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Granted: 1975-07-15
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Expires: 1993-05-29
Abstract
Abstract A push-pull amplifier with exceptionally low second order distortion products is disclosed. The amplifier comprises a pushpull stage with a feedback loop which feeds back to the input any common mode components in the output signal, that is, any components in the output of the two halves of the push-pull stage which are in phase. The feedback is degenerative in that it is fed to both halves of the push-pull stage, in phase, so as to reduce the common mode output voltage. An embodiment utilizing a cascode amplifier for each half of the push-pull stage is disclosed. The bases of the common base connected transistors in each cascode half are joined and serve as the source for the feedback signal.
Inventors
- 👤 Paul L Rebeles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:50
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/26
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
140 words
A push-pull amplifier which comprises: a. a pair of amplifiers; b. input signal coupling means for coupling an input signal to the input of each of said amplifiers, the input signal as coupled to one of said amplifiers being of opposite polarity with respect to the input signal as coupled to the other of said amplifiers; c. output signal coupling means coupled to the outputs of said amplifiers whereby an output signal which is a function of the difference in outputs of said amplifiers is obtained; d. summing means coupled to both of said amplifiers, said summing means providing a signal which is a function of the sum of the outputs of said amplifiers; and e. feedback means coupled to said summing means and coupling a feedback signal from said summing means to the input of each of said amplifiers.
Claim 2
Dependent Claim
140 words
A push-pull amplifier which comprises: a. a pair of amplifiers; b. input signal coupling means for coupling an input signal to the input of each of said amplifiers, the input signal as coupled to one of said amplifiers being of opposite polarity with respect to the input signal as coupled to the other of said amplifiers; c. output signal coupling means coupled to the outputs of said amplifiers whereby an output signal which is a function of the difference in outputs of said amplifiers is obtained; d. summing means coupled to both of said amplifiers, said summing means providing a signal which is a function of the sum of the outputs of said amplifiers; and e. feedback means coupled to said summing means and coupling a feedback signal from said summing means to the input of each of said amplifiers.
Claim 3
Dependent Claim
18 words
A push-pull amplifier as recited in claim 1 where said input signal coupling means is an input transformer.
Claim 4
Dependent Claim
47 words
A push-pull amplifier as recited in claim 1 and further including an output transformer, the primary of said output transformer being coupled to the outputs of said pair of amplifiers and said feedback signal being derived from the center tap of the primary of said output transformer.
Claim 5
Dependent Claim
16 words
A push-pull amplifier as recited in claim 1 where said pair of amplifiers are cascode amplifiers.
Claim 6
Dependent Claim
28 words
A push-pull amplifier as recited in claim 4 where said cascode amplifiers each comprise a common emitter connected transistor stage followed by a common base connected transistor stage.
Claim 7
Dependent Claim
31 words
A push-pull amplifier as recited in claim 5 where the bases of said common base connected stages are coupled and said feedback signal is derived from the circuit coupling said bases.
Claim 8
Dependent Claim
40 words
A push-pull amplifier as recited in claim 6 where said means for coupling a feedback signal to the inputs of said amplifiers couples the bases of said common base connected stages to the bases of said common emitter connected stages.
Claim 9
Dependent Claim
21 words
A push-pull connected amplifier as recited in claim 7 where said means for coupling a feedback signal includes a resistive/capacitor network.
Claim 10
Dependent Claim
23 words
A push-pull amplifier as recited in claim 1 where said feedback signal is proportional to the sum of the outputs of said amplifiers.
Claim 11
Dependent Claim
29 words
A push pull amplifier as recited in claim 1 wheRe each of said pair of amplifiers inverts the polarity of the signal applied to the input of said amplifier.
Claim 12
Dependent Claim
153 words
A push pull amplifier which comprises: a. a first pair of transistors; b. input coupling means for coupling an input signal to the base of each of said first pair of transistors, said input coupling means coupling said input signal to the base of one of said first pair of transistors with a polarity opposite to that coupled to the other said first pair of transistors; c. a second pair of transistors, the emitters of said second pair of transistors being coupled to the collectors of said first pair of transistors; d. output coupling means coupled to the collectors of said second pair of transistors; and e. feedback means coupled to the bases of said second pair of transistors, said feedback means coupling a signal having a predetermined relationship to the sum of the signals at the bases of said second pair of transistors to the bases of said first pair of transistors.
Claim 13
Dependent Claim
153 words
A push pull amplifier which comprises: a. a first pair of transistors; b. input coupling means for coupling an input signal to the base of each of said first pair of transistors, said input coupling means coupling said input signal to the base of one of said first pair of transistors with a polarity opposite to that coupled to the other said first pair of transistors; c. a second pair of transistors, the emitters of said second pair of transistors being coupled to the collectors of said first pair of transistors; d. output coupling means coupled to the collectors of said second pair of transistors; and e. feedback means coupled to the bases of said second pair of transistors, said feedback means coupling a signal having a predetermined relationship to the sum of the signals at the bases of said second pair of transistors to the bases of said first pair of transistors.
References Cited (Backward Citations)
US2835748A
Cited
US3434067A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |