| 摘要 |
PROBLEM TO BE SOLVED: To provide a distortion compensation amplifier capable of decreasing variations in its efficiency even when the output power is changed. SOLUTION: A main amplifier 7 shown in the figure comprises amplifier elements 21, 22, 23, 24 of multi-stage connection and the amplification factor of the main amplifier 7 is obtained by multiplying amplification factors of the amplifier elements with each other. When an input power is low, switches 26, 27 are thrown to the position of a third delay route 28 to turn off the amplifier element 24. Thus, even when the amplifier element 25 is turned off, the third delay route 28 permits transmission of a high frequency signal whose delay is unchanged. Further, an attenuator 25 corrects the gain change resulting from the deactivated amplifier element 24. Since no power consumption of the amplifier element 4 is needed when the output power is low, the reduction in the efficiency can be prevented and excellent linearity of the output power is obtained. COPYRIGHT: (C)2005,JPO&NCIPI
|
