HP 8753E manual Group Delay Example Measurement

3.lb activate a marker to measure the group delay at a particular frequency, press: (%ZQ and turn the front panel knob, or enter a value from the front panel keypad.

Figure 2-37. Group Delay Example Measurement

Group delay measurements may require a specific aperture (AF’) or frequency spacing between measurement points The phase shift between two adjacent frequency points must be less than 180°, otherwise incorrect group delay information may result.

4. ‘lb vary the effective group delay aperture from minimum aperture (no smoothing) to appro~ately 1% of the frequency span, press: LAvg) ~~~~~~~~~~~~

:::::. .:::..:::..:..; ....A..s.;..i. ... .2......22;;;: ......... ...A.:.:::*

When you increase the aperture, the analyzer removes fine grain variations from the response. It is critical that you specify the group delay aperture when you compare group delay measurements.

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Figure 2-38. Group Delay Example Measurement with Smoothing

244 Making Measurements