The Design Of Large Power And Wide Band Radio Frequency Amplifier Based On GaN HEMT

In recent decades,performance continuing to improve results in wireless communications widely infiltrated into personal consumption,remote office,industrial production,national security and military strategy and so on.It is essential that transmitter is a part of the wireless communication system.High linearity power amplifier gain and efficiency is a contradictory issue.It has a high efficiency but the linearity is not ideal.In this dissertation,using the third generation of semiconductor material transistor and studying the structural characteristics of the periphery of each circuit makes the efficiency,bandwidth and linearity get a good result.The main work of this dissertation is simulate design the RF power amplifier which is based GaN HEMT that is produced by Cree Company.Firstly,the dissertation introduced the categories of RF and microwave circuits,the basics of the power amplifier,some necessary parameter and linearization techniques.Then using CGH40120 F HEMT designed the single-tube RF high-power amplifier which working bandwidth is on L band.And the output power is more than 50 dBm in the whole bandwidth and the power gain is not less than 14 dB.At the same time,the addition efficiency is over 45% and the linearity of the power amplifier is also very well.To complete the large power amplifier which power is 55 dBm and power gain is 55 dB,the driver circuit and power-pushing circuit should be also designed.And the driver circuit has three power amplifiers which is used AH125,CGH40006 and CGH40045 HEMT respectively.And the power of driver circuit is 40 dBm.The power-pushing circuit is formed by four single-tube power amplifier.Finally,the whole power circuit is formed by driver circuit and power-pushing circuit and it achieves goals.