buenos
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fr 4 dielectric constant
hi.
as i could find out, most of the FR4 manufacturers give the dielectric constant at 1MHz in the datasheets.
some of them provide the Er at 1GHz.
if my board works on 400MHz (also not exact, because its a digital signal, so it has a spectrum...), then i can only estimate the Er, so my impedances on board will have a big tolerance. the manufacturing process already has a 10% tolerance.
So, how to handle this problem?
hi.
as i could find out, most of the FR4 manufacturers give the dielectric constant at 1MHz in the datasheets.
some of them provide the Er at 1GHz.
if my board works on 400MHz (also not exact, because its a digital signal, so it has a spectrum...), then i can only estimate the Er, so my impedances on board will have a big tolerance. the manufacturing process already has a 10% tolerance.
So, how to handle this problem?