Patent US4023112A successfully refreshed from Google Patents.
US4023112A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Broad band amplifier having negative feedback and a controllable amplification factor
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1975-06-12
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Granted: 1977-05-10
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Expires: 1995-06-12
Abstract
Abstract A broad band amplifier with negative feedback and controllable amplification factor for use in a carrier frequency system is described. The amplifier is preferably used as a control amplifier in the receiver of a basic group, for example, a basic 60-group of the system wherein the amplification of the amplifier is then controlled by a pilot receiver common for all the 60-groups. The amplifier includes an amplifier stage having constant amplification and which receives the pilot signal. A negative feedback path is connected via a first impedance converter from the output to the input of the amplifier stage. This path includes a capacitive voltage divider together with a second impedance converter and an RC-link. The capacitor values in the voltage divider are varied in dependence on a regulating voltage from the pilot receiver of the system, whereby the degree of negative feedback and thus the amplification of the amplifier can be controlled.
Inventors
- 👤 Bodo Kurt Adolf Duncker
- 👤 Bo Soren Tage Eberstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:22
CPC Classifications
H; H03; H03G; H03G1/00; H03G1/0005; H03G1/0035; H03G1/0052; H03G1/0064; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/10; H04B3/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
173 words
A broad band amplifier having negative feedback and a controllable amplification factor comprising: an amplifier stage with constant amplification factor and having an input adapted to receive a signal to be amplified and an output; a first impedance converter having a high impedance input and a low impedance output, the input being connected to the output of said amplifier stage for converting the high impedance output from said stage to a low impedance output; a capacitive voltage divider including variable capacitor means and having a first input connected to the output of said first impedance converter and an output; a second impedance converter having a high impedance input connected to the output of said capacitive voltage divider and a low impedance output; and connecting means for connecting the output of said second impedance converter to the input of said amplifier stage for controlling the negative feedback of the amplifier in dependence on the capacitance of the capacitor means in said capacitive voltage divider, whereby the amplification factor of the amplifier can be controlled.
Claim 2
Dependent Claim
173 words
A broad band amplifier having negative feedback and a controllable amplification factor comprising: an amplifier stage with constant amplification factor and having an input adapted to receive a signal to be amplified and an output; a first impedance converter having a high impedance input and a low impedance output, the input being connected to the output of said amplifier stage for converting the high impedance output from said stage to a low impedance output; a capacitive voltage divider including variable capacitor means and having a first input connected to the output of said first impedance converter and an output; a second impedance converter having a high impedance input connected to the output of said capacitive voltage divider and a low impedance output; and connecting means for connecting the output of said second impedance converter to the input of said amplifier stage for controlling the negative feedback of the amplifier in dependence on the capacitance of the capacitor means in said capacitive voltage divider, whereby the amplification factor of the amplifier can be controlled.
Claim 3
Dependent Claim
18 words
An amplifier as claimed in claim 1 wherein said variable capacitor means comprises at least two variable capacitors.
Claim 4
Dependent Claim
16 words
An amplifier as claimed in claim 1 wherein said connecting means includes a negative feedback link.
Claim 5
Dependent Claim
40 words
An amplifier as claimed in claim 1, wherein said capacitive voltage divider includes a capacitive series link connected to the output of said first impedance converter and a capacitive shunt link connected to the input of said second impedance converter.
Claim 6
Dependent Claim
21 words
An amplifier as claimed in claim 4, wherein said capacitive series and shunt link consist of constant but beforehand adjusted capacitors.
Claim 7
Dependent Claim
58 words
An amplifier as claimed in claim 4, wherein said capacitive series link includes two voltage dependent capacitors having the same poles connected to a common connection point, said point defining a control input of the amplifier which is adapted to receive a control voltage and wherein said capacitive shunt link includes a capacitor having a voltage independent capacitance.
Claim 8
Dependent Claim
129 words
An amplifier as claimed in claim 4, wherein said capacitive series link includes two voltage dependent capacitors having the same poles connected to a first common connection point, said point being connected to a first reference potential, and wherein said capacitive shunt link includes two further voltage dependent capacitors having the same poles connected to a second common connection point, said second point being connected to a second reference potential, a control terminal, means for connecting said control terminal to the pole of one voltage dependent capacitor in said series link which is not connected to said first common connection point, and means for connecting said control terminal to the poles of the capacitors included in said shunt link which are not connected to said second common connection point.
Claim 9
Dependent Claim
39 words
An amplifier as claimed in claim 6, wherein said voltage dependent capacitors consist of capacitor diodes, and means for connecting a control voltage to said control input of the amplifier for biasing the capacitor diodes in their reverse direction.
Claim 10
Dependent Claim
45 words
An amplifier as claimed in claim 7, wherein said voltage dependent capacitors in said series link and in said shunt link consist of capacitor diodes, and means for connecting a control voltage to said control terminal for biasing the capacitor diodes in their reverse direction.
References Cited (Backward Citations)
US2631201A
Cited
US2999169A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-09 | 1980-11-08 | 1981-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-09 | 1984-11-08 | 1985-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-09 | 1988-11-08 | 1989-05-10 | $7700.00 | Window Closed / Lapsed |