I am designing my own pcb board based on a Sodaq One V3 (I built my prototype with a Sodaq One V3 and a MAX30102) and I am currently integrating both devices in KiCAD but I have a doubt with the GPS components. The official page says the GPS is an uBlox EVA M8M and I already have the symbol and footprint, but I have doubt with the 1575.42 Mhz SAW filter U3 Component (could I use this one? B39162B9416K610), the schematic GPS circuit schematic is:
And the other doubt is about U4 component, I have no idea what that component is, I also tried to see other Sodaq boards schematics but no success since other boards do not have GPS module. Could somebody help me please?