The Research On Key Technology Of RF Front-End In S-Band TD-LTE Communication System

people and institutions have their eyes on high frequency resources above 6GHz.However in In recent years,the development of communications is mainly based on TD-LTE in China.At the same time,since the spectrum used in the communication system are congested in several frequency bands below 6GHz,many China,whether in R&D accumulation,patents or industrial capabilities,the capabilities in the field of high-frequency bands is limited.Therefore,the development of communication system will still tend to low-frequency bands in the next few years.The International Telecommunication Union and the Ministry of Industry and Information Technology have successively allocated that the only 200MHz bandwidth of spectrum resources(3400MHz?3600MHz)in the S-band to the TDD communication system,so the use of this spectrum resource will greatly promote domestic Communication development.This paper is studying the TD-LTE communication system and implement the RF front-end system in this key frequency resource.The paper has analyzed the key technologies of TD-LTE communication system and studied the structure of RF front-end of TD-LTE communication system.Then the paper has proposed the overall design of RF front-end of S-Band TD-LTE communication system according to the requirements of the article.Finally the paper has completed module design of the RF front-end circuit and overall circuit testing.The main work of this article includes:Firstly,analyzes the key technologies of the radio frequency front-end of TD-LTE communication system,and proposes the overall design scheme and structure layout of RF front-end.Secondly,complete the design of all RF front-end modules including the signal source module,the mixing module,the power detection module,the duplexer module,and the power amplifier module.And complete the layout drawing of all modules.Thirdly select the appropriate RF chip according to the index proposed by the paper,design and draw the circuit layout of each module,and finally define the circuit layout and cavity structure.Finally,the processing,debugging and testing of all circuit modules at the RF front-end has completed and the test results are analyzed.After testing,the RF front-end system can achieve the following indicators:Transmitter:The maximum output power reaches 40dBm,and the efficiency is better than 10%.Receiver:The noise figure is less than 5dB,the maximum gain is greater than 64dB,and the dynamic range is greater than 85dB.