The present invention relates to a power
amplifier device having a power
amplifier, and an object of the invention is to enable efficient use of the power
amplifier without causing any problems in the operation of the power amplifier. In order to achieve the object, a controller block 11 judges on the basis of an estimative output power value whether a power amplifier is in a first period in which it performs low
power output operation or in a second period in which it performs
high power output operation, where, in the first period, the controller block 11 activates a DC /
DC converter 2 to supply a power-supply
voltage Vdd2 as the operating power-supply
voltage to the HPA 1, and in the second period, the controller block 11 controls the DC /
DC converter 2 between active and inactive states and a switch 3 between on and off states on the basis of a detected power-supply
voltage value VM obtained from an operating power-supply voltage detecting circuit 13, so as to supply one of the power-supply voltage Vdd2 and a power-supply voltage Vdd3 as the operating power-supply voltage.