Anritsu BERTWave MP2100B, Operation Manual, Page: 47 / 382

1.5 Technical Terms
1-17
1
Outline
Eye Width
Eye Width is equivalent to Eye Height in the horizontal direction. It is
calculated from a histogram of the two eye pattern crossing points in the
time direction.
Eye Width = (t
2
–3 
2
) – (t
1
+3 
1
)
t
1
: Average time of first crossing point
t
2
 Average time of second crossing point

1
: Standard deviation of first crossing point

2
: Standard deviation of second crossing point
Figure 1.5-4 Eye Width
Eye Mask
The Eye Mask is the boundary of the eye pattern waveform time and
amplitude. The value and waveform are specified by the communications
standards.
Minimum of 0 level
Maximum of 0 level
Minimum of 1 level
Maximum jitter
Minimum of 1 level
Figure 1.5-5 Example of Eye Mask
t
1
3

1
3

2
Eye Width
t
2