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Ixiasoft
3.1.1. Backplane Measurements
The following figures are the measurement results for two backplanes, one using Megtron 6 and one using Nelco 26.25-inch backplanes. The measurements that calculate FOM include:
- Insertion loss (IL)
- Insertion loss deviation
- Return loss (RL)
Figure 16. Megtron 6 Insertion Loss
![](/content/dam/docs/us/en/683852/current/agq1516907850021.png)
Figure 17. Megtron 6 Insertion Loss Deviation
![](/content/dam/docs/us/en/683852/current/sgs1516907919344.png)
Figure 18. Megtron 6 Return Loss
![](/content/dam/docs/us/en/683852/current/nel1516907973374.png)
Figure 19. Nelco Insertion Loss
![](/content/dam/docs/us/en/683852/current/pqi1516908014030.png)
Figure 20. Nelco Insertion Loss Deviation
![](/content/dam/docs/us/en/683852/current/gyw1516908065899.png)
Figure 21. Nelco Return Loss
![](/content/dam/docs/us/en/683852/current/lgi1516908109238.png)
The bigger the FOM value, the better the quality of a channel. To pass the backplane FOM with the NRZ, NRZ with FEC, and PAM4 schemes, the channel’s quality should be at least 3 dB.