I'm working on a L-BAND project (850 MHz to 2.4 GHz) and RF components are on the top and bottom layers, so I need to use via.
PCB is 10 layer, with two dielectrics: Astra- MT77 5-mil, DK=3 (top & bottom), and FR4 5-mil, DK=4.6
I'm using "Saturn PCB toolkit" for calculating via impedance and parameters (hole,pad, spacing).
What value should I use for DK?
Do I need to have via pad on the internal layers, both GND planes and non GND layers?
Thanks in advance.
Karo