I would like to reproduce the PCB Reference Design for the CC2541DK-MINI, but I have some doubts regarding the PCB substrate material. Among the Reference Design files, it is specified:
DE104iML or equivalent substrate (Resin contents around 45%, which gives Er=4.42@2.4GHz, TanD=0.016)
Is the FR-4 included on the "equivalent substrate" category, so that I could use it instead of the above mentioned DE104iML?