S parameter G-S-G layout not grounded

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mhma

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Hi guys,

What happened in passive device s-parameter measurement if the ground pad (GSG) in the layout not connected to the ground (for example some layer is missing)

Thanks in advance
 

ur GND path is not connect ,
so expect very strange S parameters !!!!!
u can simulate it on any EM tool ,
I have simulated GSG PADS with momentum and t gave very nice results

Khouly
 

Would it still possible to get the device s-parameter after de-embedding?


Thanks
 

khouly is right. Expect strange results. The amount of unpredictability would depend on a large number of factors, frequency, ability to characterize other parameters, etc. For a simple attenuator, yes. A more complex circuit...
 

it is a spiral inductor test structure. I forgot to connect the ground pad to the ground.
 

mhma said:
it is a spiral inductor test structure. I forgot to connect the ground pad to the ground.
Click to expand...

Do you have a connection between the port 1 / port 2 grounds?
 

No connection
 

mhma said:
No connection
Click to expand...

Then it will be very difficult to interpret measurements.
Your ground pads will have some capacitive coupling to the substrate, but that current return path in the substrate is high impedance and will dominate the overall results.
 

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