| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power amplifier that can maintain a constant pass phase and input reflection while making a collector voltage Vc and an idle current Icq variable for increased efficiency at high output and low output. <P>SOLUTION: The power amplifier includes: an amplifying transistor for amplifying an input signal through an input matching circuit; means for varying the collector voltage of the amplifying transistor; a bias circuit for varying the idle current of the amplifying transistor; and a compensation circuit for varying a value of capacitance of the input matching circuit to maintain a constant pass phase and input reflection across the variations in the collector voltage and idle current for suppressing a deterioration in efficiency due to varying output power of the amplifying transistor. <P>COPYRIGHT: (C)2012,JPO&INPIT |
