Title:
EMITTER-GROUNDED AMPLIFIER CIRCUIT
Document Type and Number:
Japanese Patent JP2788869
Kind Code:
B2
Abstract:
PURPOSE: To prevent gain fluctuation caused by fluctuation in a power supply voltage by feeding back an output signal to an input point of an input stage amplifier circuit in terms of DC.
CONSTITUTION: In order to increase a resonant frequency, AC feedback is applied from an output point of a 1st stage amplifier 21 to its input point through an AC feedback loop 24. Furthermore, in order to make a feedback signal extract point and a call reception point identical to each other, DC feedback to feed back the output signal of the amplifier 21 to an input terminal 1A is conducted through a DC feedback loop 23. A DC offset of the common emitter amplifier 21 is prevented by the DC feedback. Moreover, a stabilizing circuit 25 is provided to the amplifier 21 to make the gain of the common emitter amplifier circuit stable even when a power supply voltage Vcc is fluctuated and the circuit 25 is used to make an emitter current in the common emitter amplifier circuit stable when the power supply voltage Vcc is fluctuated. Thus, gain fluctuation caused by fluctuation in the power supply voltage is prevented and dispersion in the frequency characteristic and the transmission characteristic around the resonance point is reduced.
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Inventors:
SAITO AKIHIRO
Application Number:
JP10373995A
Publication Date:
August 20, 1998
Filing Date:
April 27, 1995
Export Citation:
Assignee:
YAMAGATA NIPPON DENKI KK
International Classes:
G11B5/02; H03F1/30; H03F1/34; H03F3/343; H03G1/00; (IPC1-7): H03F1/34; H03F1/30; H03F3/343
Domestic Patent References:
| JP2159106A |
Attorney, Agent or Firm:
Naoki Kyomoto (2 outside)
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