Tektronix WVR6100 Series, Инструкция по эксплуатации

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Video and General Performance Verification
WVR6100, WVR7000, and WVR7100 Specifications and Performance Verification
2- 37
Signal Source Characterization for Eye Signal Bandwidth
Verifiying eye signal bandwidth (see page 2--52) requires a 75
Ω
RF sine wave
signal that can be connected to the 75
Ω
BNC input, and is either characterized
or automatically leveled. The results of characterization must be applied at each
measurement frequency, either by adjusting the generator level setting, or by
applying a correction to the amplitude reading from the unit under test.
The method described here uses a 50
Ω
generator, 50 to 75
Ω
min-loss pad, and
appropriate adapters and cables to connect to the 75
Ω
female BNC input of the
unit under test. The exact sequence of adapters, min-loss pad, and cables is not
critical if correct impedance is maintained in each section, and if the complete
setup is used exactly as characterized when measuring Eye bandwidth.
The absolute signal level should be chosen to give between 750 and 850 mV
p--p
at the reference frequency, as viewed on the unit under test when in Eye BW
check mode. With a setup consisting of a 50
Ω
generator, a 5.7 dB min loss pad
and appropriate adapters and cables, a base generator setting of 6.3 dBm
normally gives this result.
Characterize the test setup as follows to give a table of level setting versus
frequency setting for the signal source, resulting in constant signal level at the
connection point to the unit under test.
1. Connect the generator and the required converter, adapters, and cables to the
wideband power detector.
2. Set the generator to the reference frequency, 100 MHz, and the base level,
typically 6.3 dBm.
3.
Enter “100 MHz” into the power meter, so it applies the appropriate internal
correction.
4. Record the measured power level as the reference level in Table 2--3.
5. For each frequency listed in Table 2--3, adjust the generator level for a
reading closest to the reference level from step 4. Be sure to enter the
frequency into the power meter at each step so that it applies the appropriate
internal correction. Record each generator level setting in Table 2--3.
Characterization Process