To provide a power amplifier that can reduce distortion over a wide output power range independently of a frequency interval of two input signals.
The power amplifier is provided with a transistor(TR) 101 acting like an amplifier, an input matching circuit 103 that maximize a gain of the TR 101, an output matching circuit 105 that maximizes a saturation output of the TR 101, DC blocking capacitors 107, 109, a gate bias supply circuit 111 whose impedance for a frequency band of the input signals when viewing a gate bias supply terminal 131 from a gate terminal (G) of the TR 101 is very high, a drain bias supply circuit 113 whose impedance for a frequency band of its output signal when viewing a drain bias supply terminal 133 from a drain terminal (D) of the TR 101 is very high, and an impedance conversion circuit 115 that increases the real part of the impedance at a low frequency band equivalent to a frequency difference of the two input signals.
KUGO SHINICHI
TAJIMA TAKASHI
MATSUYOSHI TOSHIMITSU
ISHIDA KAORU
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