Patent ID: 8766727
Filing Date: 2014-07-01
Classification: H03F

Abstract:
1. A power amplification circuit that amplifies and then outputs transmission signals of a first frequency and a second frequency, the first frequency and the second frequency being different from each other, the power amplification circuit comprising: a power amplifier that amplifies the transmission signals of the first and second frequencies; a first LC parallel resonant circuit having a resonant frequency equal to the first frequency and including a switch, an inductor and a capacitor; and a second LC parallel resonant circuit having a resonant frequency equal to the second frequency and including a switch, an inductor and a capacitor; wherein the switch of the first LC parallel resonant circuit is connected in parallel with the capacitor of the first LC parallel resonant circuit; the switch of the second LC parallel resonant circuit is connected in parallel with the capacitor of the second LC parallel resonant circuit; the first and second LC parallel resonant circuits are connected in parallel with each other to an output side of the power amplifier; when the power amplifier operates with the transmission signal of the first frequency, the switch of the first LC parallel resonant circuit enters an on state and the switch of the second LC parallel resonant circuit enters an off state; and when the power amplifier operates with the transmission signal of the second frequency, the switch of the first LC parallel resonant circuit enters an off state and the switch of the second LC parallel resonant circuit enters an on state.