Title:
AUTOMATIC GAIN CONTROL CIRCUIT
Document Type and Number:
Japanese Patent JP3019569
Kind Code:
B2
Abstract:
PURPOSE: To suppress the phase fluctuation caused in the gain control in the automatic gain control circuit.
CONSTITUTION: The circuit provided with a variable gain amplifier 1, an amplitude detector 3, a low pass filter 4, a DC amplifier 5 and a reference voltage source 6 or the like and controlling a gain of the variable gain amplifier 1 to control automatically the gain is provided with a variable phase shifter 2 used to compensate the phase rotation of an output signal from the variable gain amplifier 1, an A/D converter 7 A/D-converting the gain control voltage to control the gain of the variable gain amplifier 1 and a storage means 8 reading data written in advance therein in response to an output of the A/D converter 7 and controlling a phase shift of the variable phase shifter 2 based on the data. The phase shift of the output signal of the variable gain amplifier 1 whose phase is fluctuated in response to the gain control voltage is controlled.
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| JPS6125309 | LEVEL STABILIZING CIRCUIT |
Inventors:
Fumio Tomike
Application Number:
JP36034691A
Publication Date:
March 13, 2000
Filing Date:
December 30, 1991
Export Citation:
Assignee:
NEC
International Classes:
H03G3/20; H03G3/30; (IPC1-7): H03G3/20; H03G3/30
Domestic Patent References:
| JP60230711A | ||||
| JP62123814A | ||||
| JP5253642A |
Attorney, Agent or Firm:
Suzuki Akio