Patent ID: 7123087
Filing Date: 2006-10-17
Classification: H03F

Abstract:
1. A radio frequency power amplifier, comprising: power amplifier blocks provided for different frequency bands, wherein each of the power amplifier blocks is provided with: at least two power amplifier units, having a different saturated output power level from each other, one of the units being in operation by switching; first-stage matching networks, each connected to an output node of respective one of the at least two power amplifier units, wherein output nodes of the first-stage matching networks of all of the power amplifier blocks are connected together in parallel to form a switchless junction which is provided with no switch element between each of said output nodes of the first-stage matching networks and an input node of a last-stage matching network being connected between the switchless junction and an output terminal, and wherein, when any one of the at least two power amplifier units of all of the power amplifier blocks is in operation and the other in stop of operation, the first-stage matching networks and the last-stage matching network are formed so that impedance matching is established between the output impedance of the power amplifier unit in operation and the output characteristic impedance at the output terminal, for each of the at least two power amplifier units of all of the power amplifier blocks.