DC2025_PAPER_Track8_200GbpsLanesEqualizationMethodsRequiredFixtures_Zivny.pdf

1、V1.2 200Gbps/lane.BW 1 200Gbps Lanes Equalization Methods and Required Fixture Bandwidth,S-parameter Bandwidth and Acquired Signal Bandwidth Pavel Zivny Maria Agoston,Tektronix Kiran Kumar,Tektronix V1.2 200Gbps/lane.BW 2 Abstract The 200Gbps per lane electrical standards,with typically 106 to 112 G

2、Bd PAM4 signaling,are implementing signal equalization methods more advanced than what was included in the 100Gbps per lane,which are defined around 53 GBd PAM4 signaling.In particular,the receiver equalization considered by the Standard now includes MLSD(Maximum Likelihood Symbol Detect),method use

3、d typically in slower speed standards for different media,e.g.magnetic media storage,or with complex modulations.Given this,the receiver input bandwidth must be restricted more sharply than was the case in previous,non-MLSD specifying standards.The unexpected,at least by most of the electrical worki

4、ng group experts at IEEE 802.3dj,restriction on bandwidth brings an interesting benefit:as the link bandwidth is limited to below the bandwidth of the 1.85 mm connector at the receiver,and the fixture,the electrical media,and the measurement oscilloscope are presumed linear,so the system might not n

5、eed to be specified past the bandwidth of that same 1.85 connector.But this benefit has side-effects to be verified.With the understanding of the behavior of the devices with the settings of these 200G standards,we run experiments with the different proposed bandwidth filters.We analyze the impact o

6、n the oscilloscope reference receiver.The resulting data guides both the Standard and the implementers,in particular in highlighting the unusual closeness of the Nyquist to the roll-off of the Standard.Authors Biography Pavel Zivny is the Director of the High-Speed Time-Domain Group at Multilane.He