Research On The Performance Of Small Highly Integrated High Speed Connector

In recent years,with the signal transmission rate getting higher and higher,the issue of signal integrity gets more and more attention.In military industry,with the trend of miniaturization and densification of weaponry and the highly integration of aviation system,The connector transmission rate requirements are also getting higher and higher.On the civilian side,high-speed connectors are required to walk out of the research lab and enter into all aspects of people’s lives.The requirements for mass production and low cost also follow.When the signal frequency increases and the signal rise time becomes shorter,there will be a series of signal integrity problems such as skin effect,proximity effect,dielectric loss and so on.These problems will affect the signal transmission and even produce error codes.In this paper,mainly through the study of signal integrity theory and high-speed signal transmission theory,a small high-density high-speed connector is chosen for research and its performance is analyzed.Signal integrity and high-speed transmission characteristics of the connector is mainly analyzed through theory and simulation.The high-speed performance is measured by the test and compared with the simulation results to verify the reliability of the simulation results.Finally,based on the simulation and test results,the connector is proposed to improve the design.In this paper,the current status of connector research is investigated and analyzed.It is found that the research of foreign connectors is superior to that of domestic.Although similar research has been conducted,it is mainly applied to the backplane interconnection,requiring a low height after insertion.Areas with high transmission rates still need to be filled.The small backplane connector studied in this paper has a height of only 4mm after insertion,a transmission rate of 25Gbps,and a surface-mounting method.It has a connector structure with a small size,a high transmission rate,a convenient connection,a low manufacturing cost,and can be mass-produced.It Just fills the gaps in this research field.Based on the transmission line theory,the specific structure of the connector is analyzed in this paper and a simplified model of the microstrip line model structure is adopted.Also,parameters such as characteristic impedance are theoretically analyzed.According to the theory of high-speed signal transmission,parameters such as impedance,insertion loss,return loss,and crosstalk of the connector are modeled and simulated and related tests are performed.In this paper,the 3D modeling software INVENTOR is used to draw the three-dimensional model of the connector,and the three-dimensional model of the connector is analyzed and solved using the three-dimensional electromagnetic field analysis software Ansoft HFSS.Data on parameters such as connector impedance,insertion loss,return loss,and crosstalk were obtained.For the miniaturization of connectors,which cannot be directly measured,Altium Designer is used to design PCB test fixtures.Then,according to the relevant test procedure,the S-parameter of the connector is tested using a VNA(Vector Network Analyzer)to obtain related data such as insertion loss,return loss,and crosstalk;by using TDR(Time Domain Reflectometry),the impedance performance is tested;eye diagrams and bit error rates are obtained using the BER tester system.Finally,the simulation and test results are analyzed,and it is found that the connector has much room for improvement in impedance matching and return loss.Combined with the connector’s own characteristics,using HFSS software analysis,the use of reducing the dielectric constant of 2.6,increasing the differential spacing of 0.635mm,fine-tuning the structure of the way to achieve the desired goal.The research significance of this paper lies in filling in the blank of the domestic research,carrying on the emulation and the test work to the 25Gbps backplane connector,and put forward the targeted improvement plan.