Increasing Sweep Speed

You can increase the analyzer sweep speed by avoiding the use of some features that require computational time for implementation and updating, such as bandwidth marker tracking.

You can also increase the sweep speed by making adjustments to the measurement settings. The following suggestions for increasing sweep speed are general rules that you should experiment with:

nuse swept list mode

ndecrease the frequency span

nset the auto sweep time mode

nwiden the system bandwidth reduce the averaging factor

nreduce the number of measurement points

nset the sweep type

nuse chop sweep mode

nuse external calibration

nfast Z-port calibration mode

To Use Swept List Mode

When using a list frequency sweep, choosing swept list mode can increase throughput by up to 6 times over stepped list mode. This mode takes data while sweeping through each list segment. In addition, this mode expands the list table to include test port power and IF bandwidth. Selectable IF bandwidths can increase the throughput of the measurement by allowing the user to specify narrow bandwidths only where needed.

a For in-depth information on swept list mode, refer to “Swept List Frequency Sweep” in Chapter 6, “Application and Operation Concepts. n

nFor more information on making measurements with swept list mode, refer to “Measurements Using the Swept List Mode” in Chapter 2, “Making Measurements.”

2.The frequency segments can be dellned in any of the following terms:

nstart/stop/number of points/power/IlTBW

nstart/stop/step/power/IFBW

ncenter/span/number of points/power/IFBW

ncenter/span/step/power/IFBW

Detecting IF Delay

IF delay occurs during swept measurements when the signal from the analyzer source is delayed in reaching the analyzer receiver because of an electrically long device. Because the receiver is sweeping, the delayed signal will be attenuated due to the internal IF filter.

For most measurements, swept list mode will be the optimum choice. If there is any doubt about the effect of IF delay, perform the following test:

1.Set up the measurement using the swept list mode, as in the above procedure.

2.Make the measurement and save the data trace to memory:

5-60 Optimizing Measurement Results

Page 272
Image 272
HP 8753E manual Increasing Sweep Speed, To Use Swept List Mode, Detecting if Delay