Patent ID: 6535069
Filing Date: 2003-03-18
Classification: H03F,H04B

Abstract:
A radio frequency power amplifier module used in a dual-band type mobile communication apparatus that can transmit and receive first and second band frequencies, comprising a radio frequency power output circuit including a radio frequency power output transistor used in common for both band frequencies where the second band frequency is higher than the first band frequency, where said radio frequency power output circuit comprises:an impedance connected in series to the output end of said radio frequency power output transistor; a parallel resonance circuit that is connected in series to said impedance to resonate at the predetermined even number order harmonics of the second band frequency; a series resonance circuit that is connected to said parallel resonance circuit and grounded in the other end thereof to resonate at the predetermined odd number order harmonics of the first band frequency; and an output matching circuit that is connected to said parallel resonance circuit for matching with both first and second frequency bands, wherein said impedance is set to terminate for the even number order harmonics of said second band frequency at the output end of said radio frequency power output transistor with parasitic reactance existing at the output end of said radio frequency power output transistor, and wherein said parallel resonance circuit is set to open for the odd number order harmonics of said first band frequency at the output end of said radio frequency power output transistor with said series resonance circuit, said impedance and the parasitic reactance existing at the output end of said radio frequency power output transistor.