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De-embedding PCB sparameters

Question asked by glemire on Oct 1, 2015
Latest reply on Oct 3, 2015 by Dr_joel
Hi Dr Joel,
I currently looking at de-embedding my PCB from my DUT.
My DUT consists of an SMP launch + PCB traces + package + IP. The SMP launch is used to measure electrical parameters of our transmitter on our DUT (risetime, jitter etc).

My PCB consists of SMP launch + PCB traces. Basically i want to move my reference plane back from the SMP to the package ***** as this is where many standards (PCIe etc) require the electrical measurements to be referenced.

To do this currently I usually design a replica channel on another card in the same panel with the same trace orientation etc. which is identical to my DUT channel (as possible) except that i have to place an additional SMP launch where my DUT bga is located in order to do the measurements using the VNA. I then use these s-parameters and de-embed my electrical measurements using these.

However, I have this additional SMP launch which is being de-embedded and so I have measurement errors due to the additional SMP launch.

What I am looking at doing is having a replica channel card which is basically two of PCB structures (SMP launch + PCB traces + bga + pcb traces + SMP). The idea is that I assume that this new structure is simply two of my target structures and I can extract the sparameters of the compound structure using de-embedding techniques will measure this structure and using T matrices, i will be able to determine a better estimation of the  channel by post processing this measurement to obtain the SMP launch + PCB traces + bga).

I currently use the N5225A in our lab to do these measurements

My questions are
1) is there any way to use the N5225A to do this measurement directly

1) can i set something is if this is a method that has been tried or is there a better method that you can recommend?

I have included a pdf of the measurements and the associated s-parameters with ports

Regards,
Guy  

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