US4130807A
Expired / Lapsed
US
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Feedforward amplifiers
Assignee: International Standard Electric Corp
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Filing: 1977-06-24
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Granted: 1978-12-19
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Expires: 1997-06-24
Abstract
Abstract In a feedforward amplifier the balance of the error cancelling loop can be controlled in amplitude and phase by a variable resistor and a variable capacitor connected to the input to the auxiliary amplifier. This can (a) be used for remotely controlled amplifiers to maximize the effect of phase scatter of third order intermodulation vectors, or (b) in a terminal to introduce deliberate distortion to cancel distortion introduced in line amplifiers.
Inventors
- 👤 Ralph A. Hall
- 👤 Peter E. Radley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:52
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/32; H03F1/3223; H03F1/3229; H03F1/3235
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
66 words
A feedforward amplifier comprising: a main amplifier disposed in a signal canceling loop coupled to an input of said feedforward amplifier; an auxiliary amplifier disposed in an error cancelling loop coupled between said signal loop and an output of said feedforward amplifier; and control means directly connected between said error loop and ground for controlling both the amplitude and phase of signals coupled to said output.
Claim 2
Dependent Claim
66 words
A feedforward amplifier comprising: a main amplifier disposed in a signal canceling loop coupled to an input of said feedforward amplifier; an auxiliary amplifier disposed in an error cancelling loop coupled between said signal loop and an output of said feedforward amplifier; and control means directly connected between said error loop and ground for controlling both the amplitude and phase of signals coupled to said output.
Claim 3
Dependent Claim
35 words
An amplifier according to claim 1, wherein said control means is coupled to an input of said auxiliary amplifier stage to control the amplitude and phase of error signals coupled to said auxiliary amplifier stage.
Claim 4
Dependent Claim
22 words
An amplifier according to claim 2, wherein said control means includes a variable resistor to control the amplitude of said error signals.
Claim 5
Dependent Claim
14 words
An amplifier according to claim 3, wherein said variable resistor is a PIN diode.
Claim 6
Dependent Claim
22 words
An amplifier according to claim 3, wherein said control means includes a variable capacitor to control the phase of said error signals.
Claim 7
Dependent Claim
14 words
An amplifier according to claim 5, wherein said variable capacitor is a varactor diode.
Claim 8
Dependent Claim
22 words
An amplifier according to claim 2, wherein said control means includes a variable capacitor to control the phase of said error signal.
Claim 9
Dependent Claim
14 words
An amplifier according to claim 7, wherein said variable capacitor is a varactor diode.
Claim 10
Dependent Claim
76 words
A feedfoward amplifier comprising: a signal input; a first directional coupler directly connected to said input; a main amplifier directly connected to said first coupler; a first delay line directly connected to said first coupler; a second directional coupler directly connected to said main amplifier; a third directional coupler directly connected to said first delay line; attenuation network directly connected between said second and third couplers; a second delay line directly connected to said second coupler;
Claim 11
Dependent Claim
76 words
A feedfoward amplifier comprising: a signal input; a first directional coupler directly connected to said input; a main amplifier directly connected to said first coupler; a first delay line directly connected to said first coupler; a second directional coupler directly connected to said main amplifier; a third directional coupler directly connected to said first delay line; attenuation network directly connected between said second and third couplers; a second delay line directly connected to said second coupler;
Claim 12
Dependent Claim
67 words
an auxiliary amplifier directly connected to said third coupler; a fourth directional coupler directly connected to said auxiliary amplifier, said second delay line and an output of said feedforward amplifier; and a control means having one terminal directly connected to an input of said auxiliary amplifier and the other terminal directly connected to ground to control both the amplitude and phase of signals coupled to said output.
Claim 13
Dependent Claim
67 words
an auxiliary amplifier directly connected to said third coupler; a fourth directional coupler directly connected to said auxiliary amplifier, said second delay line and an output of said feedforward amplifier; and a control means having one terminal directly connected to an input of said auxiliary amplifier and the other terminal directly connected to ground to control both the amplitude and phase of signals coupled to said output.
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) | 1981-12-18 | 1982-06-19 | 1982-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-18 | 1986-06-19 | 1986-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-18 | 1990-06-19 | 1990-12-19 | $7700.00 | Window Closed / Lapsed |