Specifications

Chapter 13 113
Stimulus Response Measurements (ESA Options 1DN and 1DQ)
Making a Stimulus Response Transmission Measurement
Stimulus Response Measurements
(ESA Options 1DN and 1DQ)
Step 5. Put the sweep time into stimulus response auto coupled mode:
Press
Sweep, Swp Coupling (SR).
Step 6. Increase measurement sensitivity and smooth the noise:
Press
BW/Avg, Res BW, 30, kHz.
Press
BW/Avg, Video BW, 300, Hz.
A decrease in displayed amplitude is caused by tracking error.
Step 7. Use peak tracking to correct the frequency offset:
Press
Source, Tracking Peak.
Tracking error occurs when the output frequency of the tracking
generator is not exactly matched to the input frequency of the analyzer.
The amplitude should return to the value that was displayed prior to
the decrease in resolution bandwidth.
Step 8. Connect the cable from the tracking generator output to the analyzer
input. Store the frequency response in trace 3 and normalize:
Press
View/Trace, More, Normalize, Store Ref (1→3), Normalize (On).
See “Normalization Concepts” on page 159 for information on
normalization.
Step 9. Reconnect the DUT to the analyzer and change the normalized
reference position:
Press
View/Trace, More, Normalize, Norm Ref Posn.
Step 10. Measure the rejection of the bandpass filter:
Press
Marker, 200, MHz, Delta, 45, MHz.
The marker readout displays the rejection of the filter at 45 MHz above
the center of the bandpass. See Figure 13-2.
Figure 13-2 Measure the Rejection Range