Multi-band amplifier and method for multi-band amplifying

PURPOSE: A multiband amplifier and a multiband amplifying method thereof are provided to perform wide band amplification by reducing performance degradation less than existing amplifier in an amplification process for a signal of various frequency bands. CONSTITUTION: A multiband amplifier(100) includes an input impedance matching unit, a cascade amplifier, and an output impedance matching unit(130). The input impedance matching unit is composed of an inductor and a capacitor. The input impedance matching unit is formed of a low pass filter, a high pass filter, and a band pass filter. The multiband amplifier amplifies a frequency band signal of more than 2 weeks. The input impedance matching unit includes a plurality of input impedance matching units(110,120) for matching input impedance of the frequency band signal.