Patent ID: 8502606
Filing Date: 2013-08-06
Classification: H03F

Abstract:
1. A power amplifying apparatus comprising: a transistor mirror circuit adjusting currents respectively flowing through a main path and a mirror path, connected in parallel to a power source terminal, according to variable resistance varying according to a gate voltage; a resistor mirror circuit connected to the transistor mirror circuit and adjusting the respective currents of the main path and the mirror path according to a fixed resistance ratio of the main path and the mirror path; a current controlling unit controlling a control current flowing through the main path with a pre-set constant current; a voltage adjusting unit providing a bias adjustment signal that corresponds to a difference voltage between a first voltage of a first node on the main path to which a current is output from the resistor mirror circuit and a second voltage of a second node on the mirror path to which a current is output from the resistor mirror circuit; and a bias circuit unit adjusting a bias of a power amplifying unit according to the bias adjustment signal from the voltage adjusting unit.