US4229625A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Repeater level control circuit
Assignee: AT&T Inc
•
Filing: 1978-12-29
•
Granted: 1980-10-21
•
Expires: 1998-12-29
Abstract
Abstract A bilateral transmission line repeater is disclosed in which opposite directions of transmission are separated into different frequency bands. The amplifiers for each direction of transmission include an automatic gain control circuit for controlling the gain of the amplifier. Gain control for the inward bound amplifier (toward a central location such as a telephone central office) is under the control of an automatic gain control signal derived from the outward bound signal as well as from the inward bound signal. Feedback around the gain control amplifier is accomplished using a current mirror circuit to avoid loading the amplifier output.
Inventors
- 👤 Jeffrey H. Derby
- 👤 Tadikonda N. Rao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:47
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/36; H04B3/38
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
101 words
A bilateral repeater for amplifying carrier signals in different frequency bands traveling in opposite directions on a common transmission line, signals in each direction of transmission being separated from signals in the other direction by filters, and a separate carrier amplifier for each direction of transmission characterized by an automatic gain adjusting circuit in at least one direction of transmission connected to said carrier amplifier in the corresponding direction of transmission, means for deriving gain control signals from the outputs of both of said carrier amplifiers, and means for combining said gain control signals to continuously control said gain adjusting circuit.
Claim 2
Dependent Claim
101 words
A bilateral repeater for amplifying carrier signals in different frequency bands traveling in opposite directions on a common transmission line, signals in each direction of transmission being separated from signals in the other direction by filters, and a separate carrier amplifier for each direction of transmission characterized by an automatic gain adjusting circuit in at least one direction of transmission connected to said carrier amplifier in the corresponding direction of transmission, means for deriving gain control signals from the outputs of both of said carrier amplifiers, and means for combining said gain control signals to continuously control said gain adjusting circuit.
Claim 3
Dependent Claim
25 words
The bilateral repeater according to claim 1 further characterized in that each of said gain control signal deriving means includes a direct current operational amplifier.
Claim 4
Dependent Claim
21 words
The bilateral repeater according to claim 2 further characterized in that one of said operational amplifiers includes a capacitive feedback path.
Claim 5
Dependent Claim
22 words
The bilateral repeater according to claim 2 further characterized in that one of said operational amplifiers includes a direct current feedback path.
Claim 6
Dependent Claim
67 words
A bilateral repeater for carrier systems having a first and a second signal amplification path, said repeater characterized means for generating gain control signals in response to output signals from said first signal amplification path and output signals from said second signal amplification path, and by controlled gain variation means for varying the gain in said second signal amplification path in response to said gain control signals.
Claim 7
Dependent Claim
67 words
A bilateral repeater for carrier systems having a first and a second signal amplification path, said repeater characterized means for generating gain control signals in response to output signals from said first signal amplification path and output signals from said second signal amplification path, and by controlled gain variation means for varying the gain in said second signal amplification path in response to said gain control signals.
Claim 8
Dependent Claim
19 words
The bilateral repeater according to claim 5 further characterized in that said controlled gain variation means comprises a variolosser.
Claim 9
Dependent Claim
35 words
The bilateral repeater according to claim 5 further characterized in that said means for generating gain control signals comprises a direct current operational amplifier responsive to the output signals from said first signal amplification path.
Claim 10
Dependent Claim
27 words
The bilateral repeater according to claim 7 further characterized in that said operational amplifier includes a reference signal input coupled to the output of said operational amplifier.
Claim 11
Dependent Claim
77 words
A bilateral repeater having separate gain controlled amplification circuits for each direction of transmission and including a first control circuit for the gain controlled amplification circuits used for one direction of transmission controlled by gain controlled amplification circuit output signals traveling in the opposite direction characterized by a second control circuit for said one direction of transmission, said second control circuit being controlled by gain controlled amplification circuit output signals traveling in said one direction of transmission.
Claim 12
Dependent Claim
77 words
A bilateral repeater having separate gain controlled amplification circuits for each direction of transmission and including a first control circuit for the gain controlled amplification circuits used for one direction of transmission controlled by gain controlled amplification circuit output signals traveling in the opposite direction characterized by a second control circuit for said one direction of transmission, said second control circuit being controlled by gain controlled amplification circuit output signals traveling in said one direction of transmission.
References Cited (Backward Citations)
US2964598A
Cited
US3603744A
Cited
US3689711A
Cited
DE2258415A1
Cited
US3823273A
Cited
US3893038A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-10-21 | 1984-04-21 | 1984-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-21 | 1988-04-21 | 1988-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-21 | 1992-04-21 | 1992-10-21 | $7700.00 | Window Closed / Lapsed |