Multi-stage RF Power Amplifier Design Based On ADS Simulation

With the rapid development of urban construction,the fourth generation of mobile communication technology has been quite mature.However,some remote rural mountainous areas are still not covered with 4G signals.The carrier network is also facing many problems,such as the mountainous region is complex and broad,it is easy to be disturbed by the external environment,the loss of the wireless transmission path is large,the population density is sparse,the cost of investment is high,and the supporting facilities are backward,and so on.The emphasis should be given to the design of the power amplifier.The 4G enclave system can solve this series of problems,greatly improve the reliability transmission distance and reduce the investment.The RF power amplifier in the system is one of the most important modules of transmission signal.Performance has always been the focus of attention.Power and efficiency is a priority for designers.Power affects the transmission distance.As a large power module,efficiency is closely related to operation cost and maintenance cost.In the environment of high peak to average power ratio and high power signal,how to design RF power amplifier with high efficiency and high linearity has become a research hotspot in the field of communication.In this paper,a multistage RF power amplifier is designed for the 4G enclave system.First,a large number of relevant documents are consulted,and the research form of power amplifier is understood.The related indexes and principles of power amplifier are introduced.The Doherty reverse structure design is selected in a variety of ways of improving the efficiency.Then,according to the requirements of base station communication and operators,the index of three level amplifier is allocated reasonably and the corresponding amplifier tube is selected.In order to meet the high gain index,two small pipes,QMGA0020 and BGA7024,are adopted in the small signal level,and BLP7G22 S and BLP8G21S-160 PV power amplifiers are selected at the driving stage and the final stage respectively.The detailed simulation analysis is made with the ADS simulation platform.Combined with the ADS simulation platform,we made a detailed simulation analysis.Finally,according to the simulation design,we produced a power amplifier object.In the central frequency of 1900 MHz simulation results show that the power additional efficiency,the peak output power(52.2dBm)and the back-off point(44.5dBm)is 62.8% and 38.5%,respectively.The efficiency of the IDPA structure is about 13.5% higher than that of the balanced structure.The two and three harmonics are more than 37 dBc.At last,the effectiveness of the simulation is verified through the physical debugging and testing.The open loop ACPR±20M is more than 32 dBc when the rated output power is 44.5dBm.Under the LTE-20 M signal,a very good open-loop ACPR index can be well combined with DPD tooling,and finally achieve a high power,high efficiency and high linearity power amplifier to meet the signal transmission requirements of 4G enclave system.