| With the rapid development of wireless communication, the demand formicrowave power amplifiers is increased higher by higher. Traditional high-efficiencybut low-linearity amplifier, or high linearity but low efficiency amplifier is difficult tomeet the practical application. High efficiency and high linearity power amplifierbecomes the only way of the development directions. As the target, this article using thelinearization techniques applied in the high efficiency amplifier structure, to get thepower amplifier’s high efficiency and high linearity requirements.The author’s main research and achievements are:1. Summarized the high-efficiency amplification techniques applicable to themicrowave power amplifiers.2. Analyzed the power amplifier’s distortion principle from different angles,analyzed the generation of memory effects in detail, and described three systemlinearization techniques.3. According to the requirements of the CDMA system amplifier, completed thesimulation and design of the Doherty amplifier with high efficiency used in CDMAsystem.4. On the basis of the Doherty amplifier, the feedforward technique is applied, toimprove the linearity of the overall amplifier further more.5. A loop control method which amplitude and phase feedback respectively isproposed, to suppress the drift phenomenon of the feedforward technique, and hadtested and verified by simulation.The actual performance of the amplifier designed by the author is：Operating bandwidth:869MHz~894MHz;Output power: more than20W;Efficiency:37%(47dBm);The third-order intermodulation: less than-48dBc. |
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