Anritsu BERTWave Series, Руководство по эксплуатации, Страница: 54 / 466

Chapter 1 Outline
1-28
Eye Height
For NRZ, eye height can be calculated by the following formula. Refer to
Figure 1.5-21.
Eye Height = (1 Level–3

1
) – (0 Level +3 
0
)

1
: 1 Level Standard Deviation

0
: 0 Level Standard Deviation
For PAM4, eye height varies depending on eye definition method and
sample method.
When Sample Timing is Independent, the maximum eye height is
measured for each eye.
Figure 1.5-10 Eye Amplitudes and Eye Heights of PAM4 Waveform
(When Sample Timing is Independent)
When Sample Timing is Track to Middle Eye Timing, eye amplitude
Upper and eye amplitude Lower are measured at the center position of
Middle Eye.
Figure 1.5-11 Eye Amplitudes and Eye Heights of PAM4 Waveform
(When Sample Timing is Track to Middle Eye Timing)
Level 2
Level 1
Level 3
Level 0
Eye Height
Upper
Eye Amplitude
Middle
Eye Amplitude
Upper
Eye Amplitude
Lower
Eye Height
Middle
Eye Height
Lower
Level 2
Level 1
Level 3
Level 0
Eye Height
Upper
Eye Amplitude
Middle
Eye Amplitude
Upper
Eye Amplitude
Lower
Eye Height
Middle
Eye Height
Lower