Study On Electromagnetic Transmission Characteristics Of High-Frequency Cables And High-Speed Connectors

With the continuous development of broadband mobile communication,cloud computing,big data and other technologies,the high-speed transmission and real-time processing of mass data has become a bottleneck technique.The electromagnetic compatibility and signal integrity of high-speed wired data transmission is one of the key difficulties of bottleneck technique.Based on the transmission line theory and signal integrity research method,this thesis systematically analyzed the transmission characteristics of Mini-SAS HD high-speed connector.(1)Based on the transmission line theory,a fast algorithm was proposed to calculate the field-to-wire coupling effect of the TWP structure.Under different external wave incidence conditions,in the range of 1MHz-5GHz,compared with the FEKO results,the maximum amplitude error of the common mode response peak current is 3.4d B?A and the maximum frequency offset is 46.4MHz.Compared with the results of existing literature,the frequency point offset is closer,the amplitude error is smaller and the calculation frequency band is wider.Furthermore,dielectric cladding cable,three-wire structure and multi-wire pair cases were calculated by extracting the unit length capacitance matrix,calculating the coupling voltage of the reference conductor and the dimension of the extension matrix respectively.(2)The transmission performance of high speed shielded signal line was modeled and simulated.The electromagnetic compatibility of metallic communication cables was tested according to IEC 62153-4-14-2012 standard.The coupling attenuation results meet the IEC 61156-5-2012 standard.Furthermore,the shielding effectiveness of Tror-03,Xyt-03 and graphite film were tested.The results of the three materials are 22.6d B,22.4d B and 7.9d B higher than the aluminum layer,respectively,and all have better thermal management performance and plasticity.(3)The signal integrity of different structures in passive link of Mini-SAS HD connector were analyzed,and the PCB model of Mini-SAS HD connector was established and simulated by HFSS.The results of the eye map showed that the dithering between the line pairs was 8ps and the S parameter results met the 12 Gbps requirements specified in SAS3.0 standard.(4)The QSFP-DD connector model was established and simulated by the HFSS.The results of the eye map showed that the dithering between the line pairs was 10 ps and the S parameter results met the 25 Gbps requirements specified in SAS4.0 standard.