Tektronix CSA8000B Series, User Manual

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Appendix B: Automatic Measurements Reference
CSA8000B & TDS8000B User Manual
B- 19
Table B- 4: RZ Measurements - Amplitude (cont.)
Name Definition
RZ Eye Opening Factor RZ Eye Opening Factor is a measure of how noise affects the vertical opening between High
and Low levels of an RZ pulse. The RZ pulse is sampled within the Eye Aperture, where the
High and Low levels are determined as the mean of the histogram of the data distribution in the
upper and lower half of the pulse, respectively. The noise levels are characterized by
σ
high and
σ
low, the standard deviations from the mean for the High and Low levels.
Where High and Low are the logical 1 and 0 levels, and
σ
high and
σ
low are the standard
deviations. See RZ Eye Aperture Parameters on B--62.
The Eye Aperture is adjustable and defaults to 5% of the RZ pulse width.
If enabled, measurement gates constrain the measurement region to the area between the Start
Gate (G1) and Stop Gate (G2). See
To Localize a Measurement on page 3--83.
This measurement requires the use of a waveform database. When this measurement is turned
on, it will automatically set the measurement system to use a waveform database if available.
See
Use a Waveform Database on page B--70.
For best results with this measurement:
H
Perform a Dark Level compensation before taking this measurement if the source of the
measured waveform is an optical channel. See
To Perform Dark-Level and User
Wavelength Gain Compensations on page 3--98.
H
Optimize the vertical resolution before taking this measurement. See To Optimize the
Vertical Resolution on page B--69.
RZ Eye Opening Factor
=
Ꮛ
( High
− σ
high )
−
( Low
+ σ
low )
(
High
−
Low
)
Ꮠ
RZ Gain RZ Gain is a defined as the amplitude gain between two waveforms. The measurement returns
the ratio between the amplitudes measured within the Eye Aperture of each of the waveforms.
Where Ampl1 and Ampl2 are the amplitudes of the two source waveforms.
The Eye Aperture is adjustable and defaults to 5% of the RZ pulse width.
If enabled, measurement gates constrain the measurement region to the area between the Start
Gate (G1) and Stop Gate (G2).
This measurement requires the use of a waveform database. When this measurement is turned
on, it will automatically set the measurement system to use a waveform database if available.
For best results with this measurement:
H
Perform a Dark Level compensation before taking this measurement if the source of the
measured waveform is an optical channel. See
To Perform Dark-Level and User
Wavelength Gain Compensations on page 3--98.
H
Optimize the vertical resolution before taking this measurement. See To Optimize the
Vertical Resolution on page B--69.
RZ Gain
=
Ampl2
Ampl1