Hot TDR Measurements

A "Hot TDR" measurement is performed on your data source by making a T22, TC22, or TDD22 measurement while your data source is sending a specified Bit Pattern length at a specified rate. The Hot TDR measurement dialog ensures that the VNA source and receiver is at frequencies other than those of the data source.

To perform Hot TDR measurements

Click File, then New Measurement and Next>, then Perform a New Calibration.

At the Setup Hardware dialog, click BASIC/ Advanced, then click Setup Hot TDR

Calculate Hot TDR Measurement Frequencies dialog box

In the above image:

The black bars represent the frequency spectra of your data source which results from the NRZ bit pattern.
The red bars represent the suggested VNA frequencies to be used to measure Hot TDR.

The VNA measurement frequencies (red bars) must be more that 10 times the IF Bandwidth from the NRZ frequencies (black bars) in order to make a valid measurement. Adjust the IF BW on the Setup Hardware dialog.

1. Calculate Spectral content of the NRZ Patterns.

Enter the Data Rate (in Gb/sec) of your data source.
Select the Patten Length of your data source.
Click Calculate

2. Preview: The suggested frequencies of the TDR measurement. These frequencies may be outside the range of the VNA. Adjust the frequencies as necessary in step 3.

3. Adjust Frequencies - Enter new frequencies, then click Calculate.

Beginning with PLTS2022, the frequency range is limited to the frequency range of the instrument. An error message is displayed if the frequency is out side the frequency of the instrument as shown below.

Last Modified:

1-Dec-2021	Added frequency range limit
25-Oct-2011	New topic