| Recently, due to the unceasing development of the mobile wireless communication technology and the wide use of 3G and 4G, the RF power amplifier becomes more and more important in base station. The requirements of high quality communication and a variety of additional service make signal's modulation more complicated. The new modulations, such as 64QAM, QPSK and 16QAM, make the PA work with low efficiency because of their high PAR when the input is small signal. Meanwhile, power amplifier is the main energy consumption module of base station. It will consume a lot of energy in the process of continuous working. Therefore, enhancing the efficiency of power amplifier will contribute to the energy saving of our country.Envelope tracking, which can make power amplifier keep high efficiency during working, is hot technology in this field. Base on the current situation of ET technology at home and abroad, this paper chose gate ET to improve the efficiency of RF power amplifier.Task completed in this subject:1,After In-depth study of power amplifier and Envelope Tracking technology, we focused on the Gate ET and verified the feasibility of gate ET.2,First of all, a power amplifier worked in 2.13GHz~2.15GHz was designed in the Advanced Design System of Agilent. In the process, a new method was used to modify the loadpull and sourcepull template. Then a coupler and a detector were designed for Gate ET. Finally, the choice of operational amplifier and MCU was made to completed the design of whole Gate ET power amplifier.3,Power amplifier and coupler were tested respectively. Then, the test of whole gate ET power amplifier is completed. The result indicated that gate ET can enhance the efficiency by 8% when the input backoff 10dBm. After depth analysis of the test result, the defect of gate ET was found .That's the compression of gain of PA. Two novel methods were presented to relieve the compression. |
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