A Method Of Estimation And Design Base On High Speed Mix Backplane

With the development of the digital technology,the more difficult to design the backplane.And the data transmittal speed become accelerated,from multi-Mbps to multi-Gbps.The speed accelerated,and the SI(signal integrity)program will coming,such as transmit line loss,crosstalk and jitter.The form of backplane is varied,for example,PCB backplane,cable backplane,and mix backplane,also include the optical backplane,but the optical backplane is in research in lab.As the important part of the interconnection,the backplane will affect the performance of the system.The backplane is Seemingly simple,but the backplane will encounter all the problem of SI.The backplane designing is the solution of SI.When the backplane design is completed,it's necessary to verifying the performance of backplane.As the actual demand,this paper proposes a mix backplane scheme.The mix backplane transmit channel is consist of PCB backplane and cable.This design follows the specification of 10 G BASE-KR,the single lane transmit speed is 10 Gbps.The mix backplane is very easy to assemble/disassemble.Because of the cable is inserted in the backplane,so the transmit channel become longer,and the channel loss don't increase.For improving the performance of the channel,the design use high speed cable,and use the aviation plug to connect the high speed cable and backplane.As the portion of mix backplane,the PCB use the high speed materiel,the low loss materiel makes the length of the propagation longer.This paper proposes a scheme to verify and estimate the performance of the mix backplane in time domain and frequency domain.Use the test instrument to measurement the mix backplane,such as TDR(Time domain reflect),S parameter,eye diagram and crosstalk,etc.By those test,verifying the channel and estimate the channel whether match the specification.Through the measurement can obtain the performance of channel,but also need to use the result to estimate the channel performance.The process of estimate is the process of deal with the measurement result,such as ILD,ICR,PSXT,ICN and COM,etc.Through the calculation,the channel performance and operation margin become intuitively.