US3701034A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Equalizer circuit for multistage feedback amplifier
Assignee: Collins Radio Co
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Filing: 1971-03-23
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Granted: 1972-10-24
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Expires: 1991-03-23
Abstract
Abstract Stability of a three stage amplifier is improved by providing a feedback loop from the amplifier output to the amplifier input, and including a compensating circuit in the loop which tends to offset phase shift of one coupling circuit in the amplifier. Mixer means is provided for mixing the feedback signal with the input signal.
Inventors
- 👤 Warren B Bruene
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:16
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/34; H03F1/347
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
130 words
A three-stage feedback amplifier tunable over a wide frequency range comprising an RF amplifier stage, a driver stage, and a power stage, each of said three stages connected to and driven into a respective coupling circuit, each of said coupling circuits exhibiting a reactance component which effects a phase shift in an amplifier signal, said phase shifts being cumulative and exceeding 180* in maximum cumulative phase shift, a feedback loop connected between the output and input of said amplifier, a compensating network in said feedback loop exhibiting a phase shift characteristic substantially equal to the phase shift characteristic of one of said coupling circuits and effectively reducing maximum cumulative phase shift thereby maintaining stability of said amplifier, and transistor mixing means for mixing the feedback signal with the input signal.
Claim 2
Dependent Claim
130 words
A three-stage feedback amplifier tunable over a wide frequency range comprising an RF amplifier stage, a driver stage, and a power stage, each of said three stages connected to and driven into a respective coupling circuit, each of said coupling circuits exhibiting a reactance component which effects a phase shift in an amplifier signal, said phase shifts being cumulative and exceeding 180* in maximum cumulative phase shift, a feedback loop connected between the output and input of said amplifier, a compensating network in said feedback loop exhibiting a phase shift characteristic substantially equal to the phase shift characteristic of one of said coupling circuits and effectively reducing maximum cumulative phase shift thereby maintaining stability of said amplifier, and transistor mixing means for mixing the feedback signal with the input signal.
Claim 3
Dependent Claim
31 words
A three-stage amplifier as defined by claim 1 wherein said compensating circuit includes a tuned circuit of similar design as said one coupling circuit and is ganged therewith for simultaneous tuning.
Claim 4
Dependent Claim
26 words
A three-stage amplifier as defined by claim 2 wherein said tuned circuit of said compensating circuit comprises part of a voltage divider in said feedback loop.
Claim 5
Dependent Claim
17 words
A three stage amplifier as defined by claim 1 wherein said compensating circuit comprises a broadband circuit.
Claim 6
Dependent Claim
89 words
In a three-stage amplifier including coupling circuits in each of said stages each exhibiting a phase shift characteristic, means for stabilizing operation of said amplifier comprising a feedback loop connected between the output and the input of said amplifier, said feedback loop including a compensating network exhibiting a phase shift characteristic substantially equal to the phase shift characteristic of one of said coupling circuits and effectively canceling the phase shift of one of said coupling circuits, and transistor mixing means for mixing the feedback signal with the input signal.
Claim 7
Dependent Claim
89 words
In a three-stage amplifier including coupling circuits in each of said stages each exhibiting a phase shift characteristic, means for stabilizing operation of said amplifier comprising a feedback loop connected between the output and the input of said amplifier, said feedback loop including a compensating network exhibiting a phase shift characteristic substantially equal to the phase shift characteristic of one of said coupling circuits and effectively canceling the phase shift of one of said coupling circuits, and transistor mixing means for mixing the feedback signal with the input signal.
Claim 8
Dependent Claim
32 words
Means for stabilizing operation as defined by claim 5 wherein said compensating circuit includes a tuned circuit of similar design as said one coupling circuit, and is ganged therewith for simultaneous tuning.
Claim 9
Dependent Claim
27 words
Means for stabilizing operation as defined by claim 6 wherein said tuned circuit of said compensating circuit comprises part of a voltage divider in said feedback loop.
Claim 10
Dependent Claim
17 words
Means for stabilizing operation as defined by claim 5 wherein said compensating circuit comprises a broadband circuit.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |