Closed TobiNakamura closed 7 years ago
The substrait thickness is not 0.2mm, its 1.6mm. The track width is a bit worrisome.
PCBWay confirmed that Dk is 3.8.
Do we want to update the trace width to get it closer to 50 Ω? At the current thickness, we'll get 52.5 Ω
Also, do we want to add fencing vias along the RF traces? According to this document, if the vias are spaced less than about 2 inches, we won't run into ground impedance issues.
Further, from the same document: Spacing the ground vias at 1/8th of a wavelength gives good isolation here also, but for the ultimate isolation available (i.e., greater than the 120 dB that a modern network analyzer can measure) it has been found that the via spacing should be kept to 1/20th of a wavelength or less.
In our case, 1/20 of the wavelength is about 3.5 cm, which is easily doable.
Never mind about the via fencing
RF traces are now 0.6mm width with 0.2mm spacing to ground.
Check CPWG, passives, wall of ground vias.