US3568073A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Logarithmic attenuator
Assignee: United States Department of the Navy
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Filing: 1968-09-09
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Granted: 1971-03-02
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Expires: 1988-09-09
Abstract
Abstract The logarithmic attenuator disclosed consists of a cascade of Lsections, each section comprising a series resistor and a shunt impedance formed by a parallel pair of forwardly biased diodes. These diodes are in series with a control voltage and consequently share a common control current. One of the diodes serves to isolate the input signal form the low impedance control voltage source, thereby allowing this voltage to be applied directly to the diodes so as to preserve their logarithmic characteristic.
Inventors
- 👤 William G Mcguffin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:04
CPC Classifications
H; H03; H03G; H03G1/00; H03G1/0005; H03G1/0035; H03G1/0052; H03H; H03H7/00; H03H7/24; H03H7/25; H03H7/253
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
121 words
A logarithmic attenuator comprising, in combination: a resistor; a first diode connected between one end of said resistor and a reference potential; a source of DC control voltage having its negative terminal connected to said reference potential; a second diode connected between the positive terminal of said source of DC control voltage and said one end of said resistor; said first and second diodes being poled such that said DC control voltage establishes the same initial amount of conduction current through both diodes; a capacitor connected across said source of DC control voltage; means for applying an input signal across the series combination of said resistor and said first diode; and means for extracting an output signal across said first diode.
Claim 2
Dependent Claim
121 words
A logarithmic attenuator comprising, in combination: a resistor; a first diode connected between one end of said resistor and a reference potential; a source of DC control voltage having its negative terminal connected to said reference potential; a second diode connected between the positive terminal of said source of DC control voltage and said one end of said resistor; said first and second diodes being poled such that said DC control voltage establishes the same initial amount of conduction current through both diodes; a capacitor connected across said source of DC control voltage; means for applying an input signal across the series combination of said resistor and said first diode; and means for extracting an output signal across said first diode.
Claim 3
Dependent Claim
147 words
A logarithmic attenuator comprising, in combination: a pair of diodes; a source of DC control voltage; means for connecting said pair of diodes in series across said source of DC control voltage such that a given amount of conduction current normally flows through said diodes as determined by the amplitude of said control voltage; a capacitor connected across said series pair of diodes; a resistor having one end thereof connected to the midpoint of said series pair of diodes, said resistor constituting the series arm of an L-shaped impedance section, the shunt arm of which includes the parallel combination of one of said conducting diodes and the other of said conducting diodes in series with said capacitor; means for applying an input signal across the series combination of said resistor and said one of said diodes; and means for extracting an output signal across this last-mentioned diode.
Claim 4
Dependent Claim
147 words
A logarithmic attenuator comprising, in combination: a pair of diodes; a source of DC control voltage; means for connecting said pair of diodes in series across said source of DC control voltage such that a given amount of conduction current normally flows through said diodes as determined by the amplitude of said control voltage; a capacitor connected across said series pair of diodes; a resistor having one end thereof connected to the midpoint of said series pair of diodes, said resistor constituting the series arm of an L-shaped impedance section, the shunt arm of which includes the parallel combination of one of said conducting diodes and the other of said conducting diodes in series with said capacitor; means for applying an input signal across the series combination of said resistor and said one of said diodes; and means for extracting an output signal across this last-mentioned diode.
Claim 5
Dependent Claim
154 words
A voltage control logarithmic attenuator having a substantially resistive characteristic which results in a minimum phase displacement of the input signal comprising, in combination: a multiplicity of L-shaped impedance sections, each section having a resistor as its series arm and a first diode as its shunt arm, said multiplicity of L-shpaed impedance sections being interconnected with one end of the resistor of each series arm being connected to the junction of said series and shunt arms to form a cascaded network; a second diode in series with each first diode; a DC control voltage source connected across all of the series pairs of diodes and establishing the same predetermined level of conduction current in each first diode; means for coupling the input signal across the first L-shaped impedance section of said cascaded network; and means for extracting an output signal across the first diode of the last L-shaped impedance section of said cascaded network
Claim 6
Dependent Claim
154 words
A voltage control logarithmic attenuator having a substantially resistive characteristic which results in a minimum phase displacement of the input signal comprising, in combination: a multiplicity of L-shaped impedance sections, each section having a resistor as its series arm and a first diode as its shunt arm, said multiplicity of L-shpaed impedance sections being interconnected with one end of the resistor of each series arm being connected to the junction of said series and shunt arms to form a cascaded network; a second diode in series with each first diode; a DC control voltage source connected across all of the series pairs of diodes and establishing the same predetermined level of conduction current in each first diode; means for coupling the input signal across the first L-shaped impedance section of said cascaded network; and means for extracting an output signal across the first diode of the last L-shaped impedance section of said cascaded network
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) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |