Patent ID: 9667202
Date: 2017-05-30
CPC Classifications: H03F

Claim:
1. A power amplifier comprising: an amplifying unit configured to amplify an input signal; an impedance varying unit connected between the amplifying unit and an output port that is for outputting an amplified signal of the input signal; and a controller configured to output a first control signal based on a level of power of the amplified input signal of the amplifying unit to control a varying of impedance of the impedance varying unit, wherein the impedance varying unit comprises: a plurality of inductors connected to each other in series; a plurality of capacitors connected to each other in parallel; a first impedance switching unit connected in parallel with at least one of the plurality of inductors and to selectively, according to the first control signal and to vary the impedance of the impedance varying unit, disconnect the at least one inductor from one or more remaining inductors of the plurality of inductors that are provided the amplified input signal; and a second impedance switching unit connected with respect to at least one capacitor of the plurality of capacitors and to selectively, according to the first the control signal and to vary the impedance of the impedance varying unit, disconnect the at least one capacitor from being connected in parallel with one or more remaining capacitors of the plurality of capacitors that are provided the amplified input signal.