| 摘要 |
<p>There is provided means for compensating a distortion for a multi-stage amplifier having gain extension characteristic. Moreover, there is provided a method for using an amplification stage having gain extension characteristic in all the stages by performing bias in the state near to class B in which the power addition efficiency is good during low output. There is provided an amplifier having gain extension characteristic for increasing a gain in accordance with increase of an input power or an output power in a certain range of the input power or the output power. In the amplifier, a base terminal of an emitter grounding amplification circuit formed by a first bipolar transistor is connected to an input matching circuit via a first impedance element not inhibiting DC current and to a cathode of a first diode for supplying bias voltage. The first diode has an anode connected to a reference power source serving as a sufficiently low impedance at high frequency.</p> |
