Research On Signal Integrity Of Display Port Connector Based On HFSS

With the rapid development of high-speed digital system,signal integrity has become the key technology of high-speed transmission,and its advantages and disadvantages have affected the reliability of the whole high-speed digital system.Display port(DP)connector is a kind of display interface.It is a digital video interface standard promoted by VESA.It is mainly suitable for connecting computer and screen,or computer and home theater system.It has a bandwidth of up to 32.4Gbps and 8bit/10bit data transmission.In addition to contact resistance,insulation resistance and electrical strength,the electrical performance of high-speed DP connector should pay more attention to signal transmission performance such as characteristic impedance,loss and crosstalk.This paper takes the display port connector as the research object1.Firstly,the signal integrity theory is used to analyze the signal transmission characteristics on DP connector.Then the three-dimensional simulation model of DP connector is established,and the signal integrity parameters such as characteristic impedance,insertion loss,return loss,near end crosstalk,far end crosstalk and eye diagram are simulated and analyzed.The simulation results show that the TDR impedance of the high-speed electrical connector has low valley and high peak,and the insertion loss,return loss,near end crosstalk and far end crosstalk meet the index requirements.According to the TDR impedance parameters and the structural characteristics of the high-speed connector,the impedance less than the index requirements occurs at the contact position between the plug end and the socket end,When the impedance is greater than the index requirement,it occurs in the bending part of the socket end.2.Aiming at the problem that the impedance of DP connector does not meet the index requirements,based on the transmission line theory,the HFSS simulation analysis is used to obtain the changes of parameter characteristic impedance,insertion loss and return loss,far end crosstalk and near end crosstalk.The improvement and optimization design are carried out by shortening the pin length,changing the pin structure,adding tin block and other methods,The TDR impedance is improved.Research shows that as long as the impedance matching is maintained or changes in a small range,the reflection,crosstalk and other problems in signal integrity will be improved.3.A higher frequency simulation is carried out for the DP connector,which is changed from 8.1GHz to 10GHz to evaluate the signal integrity of the connector under higher frequency requirements;By changing the dielectric constant of the dielectric layer,the dielectric constant of the dielectric layer is 3.2,3.5 and 3.8 respectively.The results show that the characteristic impedance changes slightly with the change of frequency;With the decrease of dielectric constant,the characteristic impedance of TDR increases,while the insertion loss,return loss,near end crosstalk and far end crosstalk change little.4.Use vector network analyzer to test the signal transmission performance parameters of DP connector.The test results of signal integrity parameters of DP connector are basically consistent with the simulation results,and slightly better than the simulation results,which shows that the simulation method,process and results in this paper are true and reliable.According to the signal integrity requirements of DP connector,this paper studies and improves its high-speed signal transmission performance by using the method of combining simulation and test,and improves the research process of signal integrity of high-speed connector.