Research And Design Of Broadband RF Power Amplifier

With the rapid development of wireless communication technology,its application in military and civil has been quite mature.As the key front-end circuit of transmitter in wireless communication system,RF power amplifier module plays a great role in communication system,but also faces the major challenge of urgent improvement.At present,the limited spectrum resources in China have become particularly crowded.Many applications put forward higher requirements for the bandwidth of RF power amplifier in wireless communication system.Therefore,the design of broadband RF power amplifier has become a research hotspot.This paper studies and designs the broadband power amplifier with the support of "Research on 5G communication oriented broadband power amplifier" of Hebei Natural Science Foundation.The work done in this paper is as follows:Firstly,the basic theory of power amplifier design is deeply studied,including design parameters,circuit matching mode,amplifier stability and design ideas.A3.4GHz?3.6GHz power amplifier used in 5G communication intermediate frequency band is designed,such as 5G communication system of China Telecom(3.4GHz?3.5GHz)and China Unicom(3.5GHz?3.6GHz).Secondly,the theoretical method of designing broadband power amplifier is deeply discussed,and the stepped impedance converter structure and dual frequency matching structure suitable for broadband circuit matching are deduced.Using these two structures,the broadband power amplifier working in S-band 3GHz?4GHz and applied to 5G communication cellular base station is designed.Then it is widely used in the design of traditional power amplifier ?/ 4.The design of bias circuit with microstrip line structure has a certain limitation on the bandwidth.A method of designing bias circuit with low-pass filter structure is used,which can isolate AC and DC channels in a wide frequency band.Finally,this structure is applied to the design of broadband power amplifier,and a broadband power amplifier with working frequency band range of 2.5GHz?4.0GHz is designed to make the coverage frequency of5 G communication cellular base station wider.