Patent ID: 7629850
Filing Date: 2009-12-08
Classification: G06F,H03F,H03G

Abstract:
1. A variable-gain amplifier comprising: an intermediate node operative to receive an electric current; a common-emitter amplifier having a collector electrically connected to the intermediate node; a first common-base amplifier having an emitter electrically connected to the intermediate node and a collector electrically connected to an output node; a base-degenerated amplifier having an emitter electrically connected to the intermediate node and a collector electrically connected to the output node; a second common-base amplifier having an emitter electrically connected to the intermediate node and a collector electrically connected to small-signal ground; wherein the intermediate node is operative to direct the electric current to the first common-base amplifier, thereby causing the variable-gain amplifier to operate in a first mode; and wherein the intermediate node is operative to direct the electric current to the base-degenerated amplifier and the second common-base amplifier, thereby causing the variable-gain amplifier to operate in a second mode.