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I'm trying to match the impedance of a RF via from bottom layer to top layer in a 6-layer PCB design. GNSS signal. Unused pad (NFP) removal activated.

The selected via size is 0.9mm pad and 0.5mm drill. No antipad defined so applying copper-to-drill default clearance (0.2mm) at inner ref planes. This results in a 0.9mm ref plane opening.

I'm using Saturn PCB tool and I wonder what data should I fill to get the correct calculation. Internal pad diameter is supposed to be the same as drill diameter? Any help/suggestion will be appreciated.

enter image description here

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  • \$\begingroup\$ I'm not familiar with that tool. Is it telling you that the impedance is 49.3 ohms at the resonant frequency, 6.915 GHz? I'm used to seeing a graphs of impedance vs frequency, or maybe an S11 plot across a frequency band that indicates how good (or bad) the match is across frequency. \$\endgroup\$
    – SteveSh
    Feb 2, 2021 at 18:33

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The tool shows a calculated via impedance of almost 50 ohms in the figure above. If your traces on top or bottom have 50 ohms, too, then you have a pretty good impedance match.

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