Patent ID: 6100760
Filing Date: 2000-08-08
Classification: H03G

Abstract:
A variable gain amplifier comprising:a load being connected to a power source;first and second current controllers having outputs being connected to said load in common;first and second current amplifier parts having outputs being connected to inputs of said first and second current controllers respectively; andfirst and second constant current sources being connected to said first and second current amplifier parts for supplying currents to said first and second current amplifier parts respectively, whereinsaid outputs of said first and second current controllers form an output of said variable gain amplifier,said first current amplifier part has a higher gain as compared with said second current amplifier part,said first and second current controllers adjust current quantities in opposite directions by a control signal,said first and second current amplifier parts amplify and output an input signal being supplied in common, andsaid first and second current controllers adjust output distribution of said first and second current amplifier parts.