Using a Network Analyzer to measure phase difference of two external RF signals

Hi all,

I raised a question on measuring the phase difference of two external RF signals using a Network analyzer (VNA)

The original question and related replies can be found here: https://www.edaboard.com/threads/208643/

I found a solution for my problem and I'm posting it here for the benefit of other users as I didn't find any thread explaining a similar measurement using a VNA...

I'm using Agilent E8361A network analyzer...

You need to configure the VNA as follows

1. In the traces menu select the "Receiver" tab, then activate one measurement, select A for the numerator and B for denominator. This gives you the ratio of the signals

2. in the "Sweep" menu, select sweep type and choose "CW", then specify the frequency of the RF signals

3. Calibration requires a power splitter and feed the two ports with two outputs of the splitter and feed an RF signal at the selected frequency. Then normalize the A/B input with "Calibration Wizard"

4. Right click on the trace and choose "phase" as the trace type

5. Then connect the two RF signals into two ports of the VNA

Then you should be able to see the phase difference of the two RF signals.

Note: As I understood, in the receiver mode, for the ratioed measurements (A/B etc.) it automatically turns off the VNA output power.
If you only want to see the input power to the VNA from singal channel, you need to manually turn off power by going into "Channel" menu and un-checking "Turn on all power..."

Thanks for vfone,biff44 for helping me on this forum, special thanks goes to Dr. Joel from Agilent technologies for answering my questions very quickly.


regards.
per_lube


PS: There might be errors/mistakes in this technique... you are most welcome for comments/improvements so that other users also can get benefit from this information