FEEDFORWORD TYPE COMMON AMPLIFIER

摘要

PROBLEM TO BE SOLVED: To provide a feedforward type common amplifier capable of efficiently using distortion suppressing quantity characteristics by controlling the frequency of a pilot signal so as not to be spurious in a band. SOLUTION: This feedforward type common amplifier which eliminates distortion based on the pilot signal, first sets the frequency of the pilot signal in a frequency fn outside the band of the feedforward type common amplifier and next resets the frequency of the pilot signal in the frequency fn+1 within the band of the feedforward type common amplifier, calculates such a controlled variable K of the frequency of the pilot signal, which is equal to or less than a level Va where the level PL of the pilot signal of the frequency fn+1 becomes spurious within the band just after the resetting by using the frequency dependency of distortion suppress quantity in the case of using the pilot signal of the frequency fn, and resets the pilot signal in the frequency fn+1 obtained by changing the frequency fn by as much as the controlled variable K.