Hello,
Substrate dielectric permittivity and thickness is critical. The width input/output traces is set to provide 50 Ohm impedance.
Datasheet specifies substrate RO4350B, Dk=3.66, the thickness is 10mil top dielectric layer. Three dielectric layers with total thickness of 32 mils.
Typical FR-4 has Dk=4.8. You can use the same layout as in the datasheet but the top dielectric layer thickness should be 12.3 mils (small variations possible, 12mils).
Hope this helps.