Design And Research Of High Order Modulation Based On Backscatter

In recent years,with the rapid development of the Internet of things,higher requirements are put forward for the communication circuit,which not only requires the circuit structure to be simplified and the size to be miniaturized,but also requires the circuit power consumption to be small,which leads to the solution of the backscatter radio.Backscatter communication technology not only simplifies the structure of communication circuit,but also has a very low power consumption.The rapid development of backscatter communication technology plays a very good role in promoting the development of the Internet of things.Therefore,backscatter communication technology has a very important practical significance.Traditional backscatter communication mostly uses ask and PSK,such as RFID,which is realized by modulating the amplitude or phase of RF carrier.But they limit the data transmission rate,because it only transmits one bit per symbol period.This dissertation focuses on the research of higher-order modulation technology,so as to improve the data transmission rate,optimize the circuit design,improve the circuit structure simplification,and realize the millimeter wave band high-order modulation.The main contents of this dissertation include:1.This dissertation first introduces the background and development of backscatter,and the practical significance of backscatter communication technology.Then,the basic principle of traditional digital modulation and the basic theory of backscatter technology are introduced,and the advantages of the scheme design are illustrated by comparing the two modulation methods.2.In this dissertation,the structure of power divider and switch combination is used to realize high-order modulation.Firstly,the ADS simulation design of 16 QAM backscatter modulation scheme working in 3GHz band is carried out.Each module in the backscatter modulation scheme is simulated respectively,and then the whole backscatter modulation module is simulated,and the final simulation results are compared with the theoretical design.3.Based on the 3GHz band,the backscatter modulation scheme is extended to the millimeter wave band to realize the 16 QAM modulation in the 30 GHz band.By comparing the simulation results,the feasibility of the design scheme is analyzed.Finally,in view of the limitation of the structure,a new modulation structure is proposed,which combines negative impedance and power divider.4.After the simulation optimization,the actual circuit design of the simulation scheme is carried out.First,the PCB circuit board design is completed,and the circuit welding,debugging and testing are carried out.The final test data are compared and analyzed with the simulation data and theoretical design respectively to evaluate whether the final test results meet the design requirements.