| 摘要 |
A power amplifier is provided to reduce impedance mismatch of an input and an output in an attenuation mode by including a match attenuation circuit reducing the impedance mismatch in an input terminal side and an output terminal side. In an amplification transistor(Tr), a base is connected to an input terminal through the first capacitance and a collector is connected to an output terminal. The amplification transistor amplifies an RF signal. A bias circuit(B2) supplies a bias current to the base of the amplification transistor. A cathode of a first diode is connected to the input terminal through the second capacitance. An anode of a second diode is connected to the output terminal through the third capacitance. A match attenuation circuit(MA) is connected between the anode of the first diode and the cathode of the second diode, reduce the impedance mismatch of the input terminal side and the output terminal side, and attenuates the RF signal. A first inductor is connected between the anode of the second diode and the power terminal. A current mirror circuit is connected to the cathode of the first diode through the second inductor and drives the first and second diode.
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