| 摘要 |
PROBLEM TO BE SOLVED: To provide a power amplifier for controlling increase in distortion of an amplified signal caused by the heat generated when the amplifier is driven, without use of a temperature detecting element. SOLUTION: According to this power amplifier, a speed-up circuit 122 transiently increases a bias to be supplied to an amplifying transistor 103 by a bias power supply unit formed of a bias circuit 111 and a power supply circuit 112 at the time of starting amplification of signal power by an amplifying transistor 103 constituting the amplifier. Accordingly, a power amplification rate of the amplifying transistor 103 can be transiently increased at the time of starting power amplification by the amplifying transistor 103. As a result, distortion of the amplified signal such as a modulated signal or the like can be reduced by shortening the time until temperature deviation caused by the heat generated by the amplifying transistor 103 is balanced in the circuit as a whole. COPYRIGHT: (C)2009,JPO&INPIT
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