De-embed S parameters for 3 Fixtures/ Pads

Hello everyone,

I am a student and have the following problem:

I would like to use the function “deembedsparams” to de-embed my DUT. Unfortunately, i am not using two fixtures or pads as intended for this function, but three. I would therefore have to de-embed all three. Can someone tell me to what extent I can use the function for my problem and what I have to consider. maybe there is a workaround solution like de-embedding each pad iteratively?

I hope someone can help me with my problem.

Many thanks in advance

Patrick

Answer 1

[Pratyush]

Hi Patrick,

To de-embed three fixtures or pads from your Device Under Test (DUT) using MATLAB's 'deembedsparams' function, which is originally designed for two-port networks, you can follow an iterative, step-by-step approach. Here’s a possible strategy:

• Obtain the S-parameters for each of the three fixtures or pads individually.
• De-embed the first fixture/pad from the DUT combined with all fixtures/pads.
• De-embed the second fixture/pad from the result of the first step.
• Finally, de-embed the third fixture/pad.
• The sequence of de-embedding might affect accuracy; choose it based on the physical and electrical configuration.
• Ensure high accuracy in the S-parameters of each fixture/pad.
• Validate your final de-embedded S-parameters against direct measurements or simulations if possible.

This approach relies on the assumption that the effects of the fixtures/pads can be independently and sequentially de-embedded, which may not hold in more complex RF systems. Accuracy and validation are crucial throughout this process.

[Patrick Wegener]

Thank you very much Pratyush!