Simulation Research On High-Speed Transmission Performance Of Gigabit Ethernet Connector

The rapid development of electronic technology makes the rising edge of high-speed signal gradually shorter and the frequency gradually higher,which makes the signal change in the transmission process of interconnecting devices,leading to the failure of the receiver to receive the true and reliable signal,so the problem of signal integrity arises.At the same time,with the rapid development of science and technology,the number of electronic equipment and systems is increasing day by day,and the performance is also continuously improving,and gradually developing towards high integration,high reliability and high sensitivity.Therefore,the electromagnetic interference problems brought by them become more and more serious.In this context,it is particularly important to solve the signal integrity and electromagnetic compatibility problems of high-speed connectors.This paper takes Gigabit Ethernet connector as the research object,and uses CST Studio simulation software to carry out simulation research on the high-speed transmission performance(including signal integrity and electromagnetic compatibility)of this connector,the main contents of the research and conclusions are as follows:Signal integrity mainly studies the S-parameter and time-domain impedance,reflecting the ability of this connector to transmit differential signals.Through simulation analysis,it is concluded that when the connector does not have external wiring cables and the simulation frequency is controlled within 810MHz,both the S parameter and time-domain impedance meet the performance index requirements;When the simulation frequency of the connector increases to 1GHz,the simulation results of the return loss and insertion loss in the S parameter do not meet the performance index requirements,and improvement design is needed.By analyzing the principle of reflection and loss,it can be determined that the inner and outer diameter dimensions of the coaxial port,the dielectric constant of the insulator,and the loss tangent angle of the insulator in the simulation scheme have improved the simulation results of return loss and insertion loss.Subsequently,by changing the inner and outer diameter dimensions of the coaxial port from r1=1.52mm,r2=3.50mm to r1=1.64mm,r2=3.77mm,and the dielectric constant of the insulator from 3.1 to 4.6,the tangent angle of the loss was changed from 0.002 to 0.0005,which changed the simulation result of return loss from-8.65dB to-10.17dB,and the simulation result of insertion loss from-0.65dB to-0.45dB,which finally met the signal integrity index requirements,and the return loss and insertion loss simulation results improved 17.57%and 44.44%respectively.In practical engineering applications,connector requires external cables,and the simulation frequency that meets the signal integrity index requirements drops to 317MHz,indicating that as the length of the transmission line increases,the quality of signal transmission will deteriorate.Electromagnetic compatibility mainly studies the radiation immunity RS in electromagnetic tolerance,that is,the ability of this connector to resist external electromagnetic interference.Its characterization parameters are the simulation results of surface current monitor,far field monitor and probe monitor.By analyzing the simulation results,it can be concluded that when the distance from the interference source to the connector is three times the length of the connector,the ability level of this connector to shield against external electromagnetic interference is better than level C;When the distance from the interference source to the connector is four times the length of the connector,the ability level of this connector to shield against external electromagnetic interference is better than level A.At the same time,by analyzing the simulation results,five key factors that affect the shielding ability level of connector are obtained:simulation frequency,location of observation points,electric field intensity of interference sources,polarization mode of interference sources and shielding shell material.