FIELD EFFECT TRANSISTOR, POWER AMPLIFIER AND MOBILE PORTABLE COMMUNICATION EQUIPMENT

摘要

PROBLEM TO BE SOLVED: To provide a power amplifier circuit which is good in linearity and smaller than a conventional one. SOLUTION: A feature of the power amplifier is being provided with a field effect transistor having an input terminal to which an input signal is supplied, an output terminal for outputting an output signal, a gate electrode to which the input terminal is connected and a drain electrode to which the output terminal is connected, a choke coil connected to the drain electrode of the field effect transistor, and a phase characteristic varying means 105 for varying phase characteristic of the field effect transistor so as to match a boundary between a linear area and a nonlinear area of the phase characteristic with the boundary between the linear area and the nonlinear area of the amplifying characteristic of the field effect transistor.