Patent ID: 7362183
Filing Date: 2008-04-22
Classification: H03F

Abstract:
1. An amplifier circuit improved in linearity and frequency band, the amplifier circuit comprising: an amplification block comprising a main transistor comprising first, second and third terminals, wherein a current flow from the second terminal to the third terminal changes according to a voltage applied to the first terminal; an auxiliary transistor comprising fourth, fifth and sixth terminals, wherein a current flow from the fifth terminal to the sixth terminal changes according to a voltage applied to the fourth terminal; a main transistor bias unit applying a bias to make the main transistor operate in a saturation region; and an auxiliary transistor bias unit applying a bias to make the auxiliary transistor operate in a sub-threshold region, wherein the second and fifth terminals are electrically connected to each other and the first and the fourth terminals are electrically connected to an input port; a first feedback block electrically connected to the third terminal; and a second feedback block electrically connected to the sixth terminal.