a bias control circuit for controlling a bias circuit coupled to an amplifier transistor . the bias control circuit receives a control voltage , and actively adjusts an equivalent resistance of the bias control circuit responsive to the control voltage , wherein the equivalent resistance is established between a first node and a reference voltage . in one embodiment , when the control voltage is increased , the equivalent resistance is gradually decreased and a current drawn by the bias control circuit is gradually increased , resulting in a quiescent current of the amplifier transistor being gradually increased .