I was wondering how the antenna matching works. In the DA14531 datasheet, there is a 1.8pF/3.3nH/1.8pF pi network right at the RF pin. Is this required to get the pin to 50 ohms?
The reason I'm asking is that the AN-B-027 app note has matching as well. Are both matching networks required (the pi network from the datasheet plus the matching network in the app note), or is the datasheet's pi network a placeholder, and can be replaced by the matching in AN-B-027?