Rohde & Schwarz R&S ZNA Series - Page 259

Concepts and features
R&S
®
ZNA
259User Manual 1178.6462.02 ─ 29
The Crossing Height is the height above "Eye Base" where the rising and falling
edges cross, "Crossing Percent" gives the same value as a percentage of the "Eye
Amplitude".
●
Opening Factor
This result is a measure of the effects of amplitude noise on the vertical eye open-
ing. Accordingly, it is equal to
(("Eye Top" - σ
Top
) - ("Eye Base" + σ
Base
)) / "Eye Amplitude"
●
SNR
Relates the "Eye Amplitude" to the noise level. Accordingly, it is equal to
"Eye Amplitude" / (σ
Top
+ σ
Base
)
Eye diagram results are only available for NRZ modulated signals.
Eye Mask Test
Furthermore, the eye diagram simulation allows to perform tests against a user-defined
eye mask:
Figure 4-18: User-defined Eye Mask
Eye mask tests are only available for NRZ modulated signals.
Rise Time Measurement
From the measured S parameters, the step responses can also be calculated using the
inverse Fourier transform. The rise time is the time the step response takes to rise from
x% to y% (0≤x≤y≤100) of the resulting step size, typically from 10% to 90%.
Optional extensions and accessories