一种用于400 Gb/s光模块测试的低成本PAM4信号BERT

Low-cost PAM4 signal BERT for 400 Gb/s optical module test

针对400 Gb/s光模块在研发和生产等环节中的测试需求,提出一种低成本四阶脉冲幅度调制(PAM4)信号比特率误码测试仪(BERT)的设计方案。首先,介绍了BERT的总体方案和实现原理,并分析了400 Gb/s光模块测试对BERT的需求和光模块内部数字信号处理(DSP)芯片的特点;其次,根据不同的应用场景,详细说明了BERT的2种硬件实现形式和软件设计要点;最后,对该BERT进行了实际测试,给出了PAM4电信号和光信号的实测结果,结果表明该BERT可以满足实际应用的需求。

In view of the test requirement of 400 Gb/s optical module in research and development and production,a low-cost 4-level pulse amplitude modulation(PAM4)signal bit error ratio tester(BERT)design scheme is proposed.Firstly,the overall scheme and implementation principle of BERT are introduced,and the requirement of 400 Gb/s optical module test for BERT and the characteristics of digital signal processing(DSP)chip inside the optical module are analyzed.Secondly,according to different application scenarios,two hardware implementation forms and software design points of BERT are detailed.Finally,the BERT is tested in practice,and the results of PAM4 electrical signal and optical signal are given,and the results show that the BERT can meet the needs of practical application.