Executing Clock Jitter Measurement

• Starting the VBA program

• Ending the VBA program

• Random jitter analysis

• Frequency analysis for periodic jitter

• Decomposition analysis for periodic jitter

• Error messages

Starting the Clock Jitter Application

Follow these steps to start up the program.

1. Press Macro > Macro 1 > Clock jitter analysis.

Note: When the macro button is not available, execute “C:\Program Files\Keysight\Network Analyzer\kjitterapp.exe”

Ending the Macro program

It is required to push the button 11 in Screen for random jitter analysis to end the program. The measurement state before the Clock Jitter Application will be recalled.

Random  jitter analysis

Overview

This analysis displays the clock frequency and the rms value of random jitter in phase-noise measurement. You can use the band marker on the screen to specify an analysis range. In this case, the analysis range is also displayed.

Note: If you select another analysis function tab (PJ Frequency/PJ Decomposition) during measurement, the current measurement is aborted. In this case, the # sign (10 in Screen) is displayed for the analysis result to indicate a possible mismatch of displayed information between the E505xA and Macro application.

Setting procedure

Screen for random jitter analysis

Select RJ from the analysis function selection tabs (default)

1. When you want to specify an analysis range, it is required to change the value of the integrated BW (5 in Screen for random jitter analysis).

2. Select a jitter display unit (2 in Screen for random jitter analysis).

4. Select the RUN button (1 in Screen for random jitter analysis).

5. The measurement starts, and the clock frequency (3 in Screen for random jitter analysis) and the random jitter rms value (4 in Screen for random jitter analysis) are displayed.

6. Click the STOP button (1 in Screen for random jitter analysis) to finish the measurement.

7. The maximum and minimum frequency (5 in Screen for random jitter analysis) can be set using this macro application. This setting does not change even by changing tabs (i.e. From Frequency tab to Decomposition tab or vica-versa), but once exiting the macro, it is initialized.

 Example of screen for random jitter analysis

Saving analysis result

You can save the analysis result to a file by following the steps below.

1. Click the tab of the analysis result that you want to save. At this time, analysis is carried out once.

2. Use the Save/Recall function to save the analysis result. For details, refer to Save and Recall Files.

Recalling analysis result

You can recall the analysis result from a file by following the steps below.

1. Use the Save/Recall function. For details, refer to Save and Recall Files

2. Press the Refresh button (8 in Screen for random jitter analysis).

Saving analysis result to a file

You can save the result of random jitter analysis to a text file by pressing the Export button (9 in Screen for random jitter analysis) .

Pressing the Export button opens the analysis result file in the Notepad application. Pressing this button during measurement writes the analysis result displayed at that time.

Frequency analysis for periodic jitter

Overview

This analysis displays the clock frequency and the RMS value of the periodic jitter when the spurious power value display is enabled in phase-noise measurement. You can use the band marker on the screen to specify an analysis range.

Setting procedure

Screen for periodic jitter frequency analysis

1. Select PJ Frequency from the analysis function selection tabs.

2. When you want to specify an analysis range, use the band marker on the phase-noise measurement screen.

3. Select a spurious sorting method displayed on the phase-noise measurement screen (3 in Screen for periodic jitter frequency analysis).

   Button	Function
   Jitter	Sorts jitters in ascending order.
   Frequency	Sorts frequencies in ascending order.

4. Select a display unit (2 in Screen for periodic jitter frequency analysis).
   

   Button	Function
   sec	Displays data in the unit of second.
   UI	Displays data in the unit of unit interval.

5. Select the RUN button (1 in Screen for periodic jitter frequency analysis).

6. The measurement starts, and the lists of clock frequencies (4 in Screen for periodic jitter frequency analysis) and periodic jitter rms values (5 in Screen for periodic jitter frequency analysis) are displayed.

7. Select the point you want to analyze from the list (5 in Screen for periodic jitter frequency analysis). When you select a point, the marker moves to the analysis point on the phase-noise measurement screen.

8. Click the STOP button to finish the measurement (1 in Screen for periodic jitter frequency analysis).

9. All the frequencies of Frequency-Jitter list measured through PJ Frequency tab are displayed. Previously, only single frequency (displayed as blue) selected in the PJ Frequency tab was displayed.

 Example screen of periodic jitter frequency analysis

Saving analysis result

You can save the analysis result to a file by following the steps below.

1. Click the tab of the analysis result that you want to save. At this time analysis is carried out once.

2. Use the Save/Recall function to save the analysis result. For details, refer to Save and Recall Files

Recalling analysis result

You can recall the analysis result from a file by following the steps below.

1. Use the Save/Recall function. For details, refer to Save and Recall Files

2. Press the Refresh button (8 in Screen for periodic jitter frequency analysis).

Saving analysis result to a file

You can save the analysis result of random jitter analysis to a text file by pressing the Export button (9 in Screen for periodic jitter frequency analysis).

Pressing the Export button opens the analysis result file in the Notepad application. Pressing the Export button during measurement writes the analysis result displayed at that time.

Decomposition analysis for periodic jitter

Overview

This analysis displays the jitter trend and histogram for jitter value analysis. The target frequency for transient measurement is linked.

Setting procedure

Screen for periodic jitter decomposition analysis

1. Select PJ Decomposition from the analysis function selection tabs.

2. Specify a clock frequency (MHz) for the periodic jitter frequency analysis (3 in Screen for periodic jitter decomposition analysis). Frequencies added here are saved in the list.

3. Enter the period jitter frequency you want to analyze (4 in Screen for periodic jitter decomposition analysis). Frequencies entered here are saved in the list of jitter values (5 in Screen for periodic jitter frequency analysis).

4. Select an analysis function (5 in Screen for periodic jitter decomposition analysis).
   

   Button	Function
   Jitter Trend	Displays the jitter trend and analyzes the total jitter.
   Histogram	Displays the histogram and analyzes the total jitter.
   PJ Separation	Displays the histogram and Gaussian and analyzes the total jitter and periodic jitter.

5. Turns on/off the jitter trend auto correction function (6 in Screen for periodic jitter decomposition analysis).
   
   The average of the narrow band measurement frequencies used in transient measurement is set to the phase reference frequency offset value.
   
   To turn on this function, select the Auto Trend Correction checkbox.

6. Select a display unit (2 in Screen for periodic jitter decomposition analysis).
   

   Button	Function
   sec	Displays data in the unit of second.
   UI	Displays data in the unit of unit interval.

7. Select the RUN button (1 in Screen for periodic jitter decomposition analysis).

8. The previous analysis result is cleared.

9. Measurement starts, and the analysis result is displayed.

• If fitting fails, ? (question mark) is added at the end of the analysis result.

9. Click the STOP button to finish the measurement (1 in Screen  for periodic jitter decomposition analysis).

Example screen for periodic jitter decomposition analysis

Adjusting the position where the analysis result is displayed

You can display the result of periodic jitter decomposition analysis at your desired position. Clicking the Adjust Position button (7 in Screen for periodic jitter decomposition analysis) will bring up another window on which you can adjust the display position as shown in the figure below.

Saving analysis result

You can save the analysis result to a file. Follow the steps below.

1. Click the tab of the analysis result that you want to save. At this time analysis is carried out once.

2. Use the Save/Recall function to save the analysis result. For details, refer to Save and Recall Files.

Recalling analysis result

You can recall the analysis result from a file by following the steps below.

1. Use the Save/Recall function. For details, refer to Save and Recall Files.

2. Press the Refresh button (8 in Screen for random jitter analysis).

Saving analysis result to a file

You can save the result of random jitter analysis to a text file by pressing the Export button (9 in Screen for periodic jitter decomposition analysis).

Pressing the Export button opens the analysis result file in the Notepad application. Pressing the Export button during measurement writes the analysis result displayed at that time.

Error messages

If an error occurs during clock jitter measurement, a dialog box appears and the measurement stops. You may encounter the following messages.