FAQs from Rohde & Schwarz

600 ms RF Pulse/Burst Measurement with Accuracy of less than 1 ms?


How can we measure a pulse length of 600 ms with an accuracy of less than 1 ms with the FSIQ? The maximum accuracy of pulse length measurement should be better than indicated in the data sheet. Time domain problem seems to be 500 display points. 1% FS (full scale) of a pulse length of 600 ms means +/- 6 ms, and this is too much. Which settings are necessary to get more accuracy?


You cannot make this in one sweep, but you have to split this up into two sweeps

and the trigger offset. Then you can measure the falling edge.

Please keep in mind that you also must measure the rising edge, as the

trigger event and the sweep have an offset.

First, you have to measure the offset at the rising edge.

Start a video trigger and watch the rising edge of your pulse signal.

Now select a level for the video trigger point (for example 50 % level of rising edge).

This will be your new trigger point.

Then select an offset delay of 595 ms.

Your display starts 595 ms after the video trigger and you should select 0.5 ms per division.

Now you should see a falling edge at the end of the display screen (screen starts at 595 ms and ends at 600 ms).

If you do not see the falling edge and the level is high, you can use a 598 ms offset. If the level is low, then you should use 592 ms, and so on.

The accuracy will be approximately 100 times better than with the entire 600 ms pulse displayed on the screen.