| 摘要 |
PROBLEM TO BE SOLVED: To allow a high frequency power amplifier to cope with a requirement of miniaturization without provision of a harmonic control circuit as a separate circuit from the amplifier circuit. SOLUTION: The high frequency power amplifier is provided with a high frequency transistor(TR) Q11, an input matching circuit, an output matching circuit and a bias circuit S1 that is connected to an output electrode of the high frequency TR Q11 and consists of a distributed constant line L15 and an inductor L14 connected in series with the line L15. The bias circuit S1 has a combined reactance component acting like part of the output matching circuit and reactance a resonance point with respect to higher order harmonies by the distributed constant line L15 and the inductor L14. Since the bias circuit S1 also acts like a harmonic control circuit that supplies a DC current and finely adjusts the resonance point to eliminate higher order harmonics, it is not required to add a separate harmonic control circuit to the high frequency power amplifier and then the high frequency power amplifier much more copes with a requirement of miniaturization.
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