This stack-up supplies an adjacent ground and power airplane at L10 and L11, which makes the L12 (because of higher isolation) excellent to route analogue signals. Arlon AD2000: This is another dielectric material with an exceedingly very low dielectric constant and decline tangent. It’s a typical choice for 8-layer PCBs. https://12-layerautomotivecentral38260.aboutyoublog.com/33007033/5-essential-elements-for-internet-radio-receiver-pcb