Title:
VARIABLE GAIN AMPLIFIER CIRCUIT
Document Type and Number:
Japanese Patent JP3833923
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a variable gain amplifier circuit wherein circuit current can be increased when a large signal is inputted and distortion characteristic is improved.
SOLUTION: A second load element 12 is connected between an emitter of a first transistor 1 and emitters of a second and a third transistors 2, 3, and the emitters of the second and the third transistors 2, 3 are connected with a current source 31. Base voltages of the first, the second and the third transistors 1-3 and current of the current source 31 are controlled by a voltage control circuit 32, so that distortion characteristic is improved when a large signal is inputted, and input impedance characteristic is stabilized. Further, a large attenuation can be obtained.
Inventors:
Hiroshi Fujino
Application Number:
JP2001328579A
Publication Date:
October 18, 2006
Filing Date:
October 26, 2001
Export Citation:
Assignee:
New Japan Radio Co., Ltd.
International Classes:
H03G3/10; (IPC1-7): H03G3/10
Domestic Patent References:
| JP2002344266A | ||||
| JP2001292043A | ||||
| JP10341122A | ||||
| JP62132412A | ||||
| JP6097712A | ||||
| JP57196609A |
Other References:
Ken Leong Fong,"Dual-band high-linearity variable-gain low-noise amplifiers forwireless applications",ISSCC 1999 ,1999年,p.224-225
Attorney, Agent or Firm:
Tsutomu Azumako