Patent ID: 6917823

Claim:
A cellular telephone adapted to be used in a CDMA system, comprising: an antenna which receives a signal from a cell-site station and transmits a signal to the cell-site station, a duplexer connected to the antenna, a receiver connected to the antenna through the duplexer so as to receive a transmitting power controlling signal transmitted from the cell-site station, a variable amplitude amplifier which controls output power of a signal transmitted from the antenna to the cell-site station, a power amplifier which amplifies signal output from the variable amplitude amplifier, a memory which stores a plurality of bias conditions of the power amplifier and a plurality of gains of the variable amplitude amplifier corresponding to output power of a signal transmitted from the antenna, and a controller which controls a bias condition of the power amplifier and a gain of the variable amplitude amplifier based on the transmitting power controlling signal when the receiver receives the transmitting power controlling signal transmitted from the cell-site station, wherein the controller controls the bias condition of the power amplifier using a pulse width modulation signal as a bias control signal.