| Power amplifier,which plays a particularly important role in the communication base station,is widely used in mobile wireless communications,aerospace military,radar satellites and other fields.The promotion of the efficiency,which can reduce the cooling costs,also drives the development of power amplifier with higher efficiency.In this thesis,Class F Doherty power amplifier is designed based on the mature Doherty technology with the latest high-efficiency Class F amplifier technology.At the same time,in order to meet the demand of high frequency band,high bandwidth and high speed transmission in the future 5G communication,an LTCC millimeter-wave microstrip antenna is also designed in this thesis.First,achievement and research in domestic and overseas about Class F Doherty power amplifier in recent years are summarized.Meantime,the recent research and development prospect of 5G millimeter-wave microstrip array antenna in domestic and overseas is also introduced briefly.Secondly,the basic theory of Class F power amplifier is introduced.The mathematic derivation of flattening voltage and current waveform is described in detail.Two kinds of commonly used harmonic control network design methods are introduced and contrasted.Meantime,the theory and working status of Doherty power amplifier,which provide the theoretical support for the design of power amplifier,are also introduced in detail.Then a 1.7~1.9GHz Class F Doherty power amplifier is designed by using Cree semiconductor company's GaN transistor CGH40010 F.The main power amplifier works in Class F,auxiliary power amplifier works in Class C,using of two symmetrical structure.The final results show that the saturation output power in 1.7 ~ 1.9GHz band is not less than 43 dBm,the average efficiency of the drain is higher than 70%,while the back-off efficiency is more than 50%.Relative to the traditional Doherty amplifier,the efficiency is greatly improved.Millimeter-wave microstrip antenna is the future development trend of 5G antenna.The working principle,characteristic parameter,analysis method and feeding mode of the microstrip antenna are introduced simply.Then a 60 GHz microstrip array antenna is simulated and designed.A 4×4 microstrip array antenna is designed by using the LTCC process,and the design of the cell is made with the slot coupling feed technique.HFSS is used to simulate the antenna array.The simulation results show that S11<-15 dB and the average gain G_a >13dBi in the range of 58~62GHz. |
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