GAIN VARIABLE HIGH FREQUENCY AMPLIFIER CIRCUIT AND HIGH FREQUENCY INTEGRATED CIRCUIT WITH GAIN VARIABLE AMPLIFICATION FUNCTION

Title:

GAIN VARIABLE HIGH FREQUENCY AMPLIFIER CIRCUIT AND HIGH FREQUENCY INTEGRATED CIRCUIT WITH GAIN VARIABLE AMPLIFICATION FUNCTION

Document Type and Number:

Japanese Patent JP2003069356

Kind Code:

A

Abstract:

To provide a gain variable high frequency amplifier circuit with low distortion and whose noise characteristic is not deteriorated even when the amplifier circuit is used for an input signal with a high power dynamic range.

A transmission line 20 for configuring a distributed constant circuit of an input matching circuit 12 and a transmission line 42 for configuring a distributed constant circuit of an output matching circuit 34 are connected to the variable high frequency amplifier circuit by a switch 50 that can select interconnection of the lines 20, 42 or disconnection of the lines 20, 42. In the case of closing the switch 50 and inactivating an FET 22, since an input signal is outputted while being passing through the switch 50, the gain can be changed in comparison with the case of opening the switch 50 and allowing the FET 22 to amplify the input signal.

Inventors:

DOKI HIROSHI
ITO YUICHI
MURAKAMI YOSHIHIDE

Application Number:

JP2001252857A

Publication Date:

March 07, 2003

Filing Date:

August 23, 2001

Export Citation:

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Assignee:

MURATA MANUFACTURING CO

International Classes:

H03F3/60; H03F3/72; H03G3/02; (IPC1-7): H03G3/02; H03F3/60; H03F3/72

Attorney, Agent or Firm:

Kenji Yoshida (2 outside)

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