New linearization method using interstage second harmonic enhancement

Efficient use of the frequency spectrum necessitates the use of modulation formats such as pi/4-DQPSK, which requires linear amplification to minimize spectral regrowth. A new Linearization technique is presented that allows a more efficient operation of these linear amplifiers by combining both the advantage of the transparent nature of feed-forward linearization with the efficiency of feedback linearization. The method of convolution is used to analyze the amplifier characteristics and to determine how linearization c an be achieved, This method is verified experimentally and proves that by c areful use of the second harmonic component, a new method of linearization has been realized.