ATTENUATOR SWITCH AND CELLULAR PHONE TERMINAL DEVICE USING IT

Japanese Patent JP3934067

B2

PROBLEM TO BE SOLVED: To provide a cellular phone terminal device capable of supplying high quality telephone conversations, with a simplified configuration for performing band switching control and gain control in a space-saving body.
SOLUTION: A switch gain controller 271 is provided at a high frequency unit 270 for amplifying a high frequency signal outputted from an intermediate frequency unit 230 and supplying it to an antenna 300. The switch gain controller 271 includes an attenuator switch 272 for conducting band selection switching on two bands outputted from the intermediate frequency unit 230, and controlling gain of a high frequency signal in the selected band. The attenuator switch 272 comprises a signal line 47 composed of a variable resistor 41 connecting a signal input unit 43 and a signal output unit 45, and a signal line 48 arranged in parallel to the signal line 47 and composed of a variable resistor 42 connecting a signal input unit 44 and a signal output unit 46. The variable resistors 41 and 42 are controlled by a common gain control voltage, and set up so that the range of gain control voltage for varying a resistance value is not overlapped.

Masahiko Inamori
Takashi Yamamoto
Masao Nakayama
Motoyoshi Kaname

JP2003029694A

June 20, 2007

February 06, 2003

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Matsushita Electric Industrial Co., Ltd

H03G3/30; H03G1/00; H03G3/20; H03H11/24; H04B7/005; H04M1/74; (IPC1-7): H03G3/30

JP2039681A
JP8228138A
JP11186921A

Akio Miyai

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