5G RF Front-end Standard Module Design

Based on the fifth-generation mobile networks,which is an inevitable trend in the future mobile development,this paper has standardized and design of the RF receiving front-end module.Massive MIMO technology and the use of higher frequency bands are the core technologies of 5G,which also place higher requirements on future mobile communication equipment and bring certain difficulties to the design of RF front-ends.The loss is large between antenna and radio frequency circuit.How to reduce the loss in transmission is the focus in this design.Based on this using purposes,this paper proposes a model that standardizes the5 G radio frequency front-end module.The single-channel of the radio frequency circuit and antenna is designed.And the standard module is designed to make the antenna to the radio frequency circuit close infinitely.So that the signal received by the antenna can directly enter the radio frequency circuit for amplification and mixing without the longer transmission line.After processing,the down-conversion function is completed to output the intermediate frequency signal that can be directly used.At the same time,the loss between the antenna and the radio frequency circuit is reduced.In addition,we can freely combine modules according to the different requirements.And then we can use these modules to form the array antenna which can apply to different application scenarios.Based on the 5G mobile communication system,In this paper we study and design the RF front-end receiving system.During the design process,the theoretical research about the characteristics,key technology and the basic structure of receiver is studied firstly.Then the function and specification requirements of designed antenna and RF circuit is proposed.The specification is analyzed and defined at the same time.Finally,on the basis of theoretical analysis,the designing plan is worked out.In the plan,the designing of standard module is divided into three part,antenna,amplifier and down converter.In this paper,we used a circularly polarized microstrip antenna which used a single point feed to be the part of antenna.The antenna is modeled and simulated by using the electromagnetic software ANSOFT HFSS.The final designed antenna worked at 4.9GHz and the bandwidth is 300 MHz.At the center frequency,the gain in the forward direction is 6.95 d B.The part of RF receiving channel is used the form ofonce down conversion.In this part,we carries out scheme design,index determination,and device selection for them..Besides,we complete Schematic design,layout design and physical testing.Through the test,every indicators met the design requirements.According to the test results,the RF circuit can work at the frequency band which center frequency is 4.9GHz,and the bandwidth is 200 MHz.In this design,the LO signal is 4.5GHz and the IF frequency is 400 MHz.The gain of RF circuit is 37.5d B and the noise figure is 3.14 d B.All in all,we verified the feasibility of the program by physical processing and testing.The output signals of each module and the system's down-conversion function met the expected results.After being designed by integrated circuits,this module can provide standard units for 5G access antennas and base station antenna arrays.