| 摘要 |
PURPOSE: An apparatus and a method for controlling the bias of a power amplifier are provided to economically enhance the efficiency of a bias modulator by forming a linear amplifier with a few elements. CONSTITUTION: A first controller(210) generates a first controlling signal in the event a first current amount of a first current output from a switching regulator is lower than an envelope current amount, which corresponds to an input envelope signal. A current supplying unit(216) outputs a second current with a second current amount, which is the current amount resulting from the subtraction of the first current amount from the envelope current amount. A second controller(220) generates a second controlling signal in the event the first current amount exceeds the envelope current amount. A current eliminating unit(226), according to the second controlling signal, eliminates a third current with a third current amount, which is the current amount resulting from the subtraction of the envelope current amount from the first current amount, from the first current. A power amplifier is connected to the output of the switching regulator and a bias controlling device. |
