| 摘要 |
PURPOSE:To improve distortion and to utilize electric power effectively by branching an input signal into two, adjusting an amplifier A for one signal and the other signal to a level which is larger than and <=2 times as high as the level of the amplifier A, and amplifying the difference from the output of the amplifier A by an amplifier B, and mixing it with the output of the amplifier A. CONSTITUTION:A means 20 branches the signal 1 at an input terminal into signals S and S, and an amplifier A21 amplifies one signal S. Adjusting means 9 and 23 adjust the other signal S to a level higher than and <=2 times as high as the level of the amplifier A21, and amplifier B22 amplifies the difference between the output of the amplifier A21 and the output of the means 9 and 23. Then, a 3dB coupler 24 mixes the output of the amplifiers A and B and outputs the resulting signal to an output terminal. Consequently, distortion is improved and the electric power of the amplifier B for distortion amplification is utilized effectively; even if a fault occurs to the amplifiers, a communication circuit is never disconnected, thereby improving the reliability.
|
