US3652952A
Expired / Lapsed
US
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Electronically variable line build-out network
Assignee: AT&T Inc
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Filing: 1970-05-19
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Granted: 1972-03-28
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Expires: 1990-05-19
Abstract
Abstract A variable line build-out network for simulating cable lengths from substantially zero feet to L feet having at least two parallel paths each having a different transmission loss characteristic. In a two path line build-out network embodying the invention, the first path has an amplifier having gain X followed by a section of cable of length L, or an RC network to simulate the characteristics of such a section of cable but having no delay, and produces in response to an input pulse an output having two components; the first being identical in shape to the input pulse but of reduced amplitude (X < 1) and the second component representing the distortion introduced by a section of cable of length XL. The second path has an amplifier of gain 1 - X and where a section of cable was employed in the first path, a pure delay circuit in series therewith. When the outputs of the two paths are combined, the result is a pulse whose shape is identical to that which would have been produced if the input pulse had been transmitted through a cable of length XL.
Inventors
- 👤 William I-Hsuan Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:48
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/40
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
200 words
A multiple path electronically variable line build-out network comprising, in combination, a first path containing an amplifier connected to receive input signals from a source of signals, a second path containing an amplifier in series with an RC network simulating a cable of length L the input of said amplifier in said second path being connected to receive said input signals, a third path containing an amplifier in series with an RC network simulating a cable of length 2L the input of said amplifier in said third path being connected to receive said input signals, and additional paths each such additional path containing an amplifier in series with an RC network simulating a cable of length NL the input of said amplifier being connected to receive said input signals where N is the number of multiple paths including such additional paths less 1 and the gain of the amplifiers is determined by the equation: where X is the independent variable, N is the total number of controlled gain amplifiers less 1, fn(X) is the gain of the nth amplifier as a function of X and m is the dummy variable and adder means to combine the output of each path.
Claim 2
Dependent Claim
200 words
A multiple path electronically variable line build-out network comprising, in combination, a first path containing an amplifier connected to receive input signals from a source of signals, a second path containing an amplifier in series with an RC network simulating a cable of length L the input of said amplifier in said second path being connected to receive said input signals, a third path containing an amplifier in series with an RC network simulating a cable of length 2L the input of said amplifier in said third path being connected to receive said input signals, and additional paths each such additional path containing an amplifier in series with an RC network simulating a cable of length NL the input of said amplifier being connected to receive said input signals where N is the number of multiple paths including such additional paths less 1 and the gain of the amplifiers is determined by the equation: where X is the independent variable, N is the total number of controlled gain amplifiers less 1, fn(X) is the gain of the nth amplifier as a function of X and m is the dummy variable and adder means to combine the output of each path.
Claim 3
Dependent Claim
226 words
A multiple path electronically variable line build-out network comprising, in combination, a first path containing an amplifier in series with a section of cable providing delay the input of said amplifier being connected to receive signals from a source of signals, a second path containing an amplifier in series with a section of cable of length L and a section of cable providing delay, the input of said amplifier in said second path being connected to receive said signals from said source, a third path containing an amplifier in series with a section of cable of length 2L and a section of cable providing delay the input of said amplifier in said third path being connected to receive said signals from said source, additional paths each containing an amplifier in series with a section of cable of length NL and a section of cable providing delay the input of each said amplifier being connected to said source, where N is the number of multiple paths including such additional path less 1 and the gain of the amplifiers is determined by: where X is the independent variable, N is the total number of controlled gain amplifiers less 1, fn(X) is the gain of the nth amplifier as a function of X and m is the dummy variable and adder means to combine the output of each path.
Claim 4
Dependent Claim
226 words
A multiple path electronically variable line build-out network comprising, in combination, a first path containing an amplifier in series with a section of cable providing delay the input of said amplifier being connected to receive signals from a source of signals, a second path containing an amplifier in series with a section of cable of length L and a section of cable providing delay, the input of said amplifier in said second path being connected to receive said signals from said source, a third path containing an amplifier in series with a section of cable of length 2L and a section of cable providing delay the input of said amplifier in said third path being connected to receive said signals from said source, additional paths each containing an amplifier in series with a section of cable of length NL and a section of cable providing delay the input of each said amplifier being connected to said source, where N is the number of multiple paths including such additional path less 1 and the gain of the amplifiers is determined by: where X is the independent variable, N is the total number of controlled gain amplifiers less 1, fn(X) is the gain of the nth amplifier as a function of X and m is the dummy variable and adder means to combine the output of each path.
Claim 5
Dependent Claim
149 words
A variable line build-out network for a digital transmission system to simulate a cable of length XL comprising, in combination, an input terminal connected to receive digital signals, a summing point, a first transmission path between said input terminal and said summing point having an amplifier of gain X whose input is connected to said input terminal and Whose output is connected to an RC network simulating a cable of length L and having no delay whose output is connected to said summing point, and a second transmission path between said input terminal and said summing point having an amplifier of gain (1 - X) so that the transfer characteristic between said input terminal and said summing point is (substantially identical to) approximated by the following equation (H(X1S) e X S) H(X,S) e X S where H(X,S) is the transfer characteristic of a section of cable of length X.
Claim 6
Dependent Claim
149 words
A variable line build-out network for a digital transmission system to simulate a cable of length XL comprising, in combination, an input terminal connected to receive digital signals, a summing point, a first transmission path between said input terminal and said summing point having an amplifier of gain X whose input is connected to said input terminal and Whose output is connected to an RC network simulating a cable of length L and having no delay whose output is connected to said summing point, and a second transmission path between said input terminal and said summing point having an amplifier of gain (1 - X) so that the transfer characteristic between said input terminal and said summing point is (substantially identical to) approximated by the following equation (H(X1S) e X S) H(X,S) e X S where H(X,S) is the transfer characteristic of a section of cable of length X.
Claim 7
Dependent Claim
143 words
A variable line build-out network for a digital transmission system to simulate a cable of length XL comprising, in combination, an input terminal connected to receive pulse signals, a summing point, a first transmission path between said input terminal and said summing point having an amplifier of gain X whose input is connected to said input terminal and whose output is connected to a predetermined section of cable of length L whose output is connected to said summing point, and a second transmission path between said input terminal and said summing point having an amplifier gain (1 - X) so that the transfer characteristic between said input terminal and said summing point is (substantially identical to) approximated by the following equation (H(X1S) e X s) H(X,S) e X S where H(X,S) is the transfer characteristic of a section of cable of length X.
Claim 8
Dependent Claim
143 words
A variable line build-out network for a digital transmission system to simulate a cable of length XL comprising, in combination, an input terminal connected to receive pulse signals, a summing point, a first transmission path between said input terminal and said summing point having an amplifier of gain X whose input is connected to said input terminal and whose output is connected to a predetermined section of cable of length L whose output is connected to said summing point, and a second transmission path between said input terminal and said summing point having an amplifier gain (1 - X) so that the transfer characteristic between said input terminal and said summing point is (substantially identical to) approximated by the following equation (H(X1S) e X s) H(X,S) e X S where H(X,S) is the transfer characteristic of a section of cable of length X.
Claim 9
Dependent Claim
225 words
A multiple path electronically variable line build-out network comprising, in combination, a first path containing an amplifier connected to receive input signals from a source of signals, a second path containing an amplifier in series in an RC network having a gain and phase characteristic opposite that of a cable of length L, the input of said amplifier in said second path being connected to receive said input signals, a third path containing an amplifier in series with an RC network having a gain and phase shift opposite that of a cable of length 2L the input of said amplifier in said third path being connected to receive said input signals, and additional paths each such additional path containing an amplifier in series with an RC network having a gain and phase shift opposite that of a cable of length NL the input of each said amplifier being connected to receive said input signals where N is the number of multiple paths including such additional paths less 1 and the gain of the amplifiers is determined by the equation: where X is the independent variable, N is the total number of controlled gain amplifiers less 1, fn(X) is the gain of the nth amplifier as a function of X and m is the dummy variable and adder means to combine the output of each path.
Claim 10
Dependent Claim
225 words
A multiple path electronically variable line build-out network comprising, in combination, a first path containing an amplifier connected to receive input signals from a source of signals, a second path containing an amplifier in series in an RC network having a gain and phase characteristic opposite that of a cable of length L, the input of said amplifier in said second path being connected to receive said input signals, a third path containing an amplifier in series with an RC network having a gain and phase shift opposite that of a cable of length 2L the input of said amplifier in said third path being connected to receive said input signals, and additional paths each such additional path containing an amplifier in series with an RC network having a gain and phase shift opposite that of a cable of length NL the input of each said amplifier being connected to receive said input signals where N is the number of multiple paths including such additional paths less 1 and the gain of the amplifiers is determined by the equation: where X is the independent variable, N is the total number of controlled gain amplifiers less 1, fn(X) is the gain of the nth amplifier as a function of X and m is the dummy variable and adder means to combine the output of each path.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-28 | 1975-09-27 | 1976-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-28 | 1979-09-27 | 1980-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-28 | 1983-09-27 | 1984-03-28 | $7700.00 | Window Closed / Lapsed |