I have a working ZigBee system based on ATMEGA256RFR2. (Datasheet) On page 33 you can check the RF system of this IC.
Now I want to use a FEM module to increase the performance and I found the SKYWorks SKY66114-11 which is designed for this exact purpose. (Datasheet)
On the ATMEL chip there is a balanced output of RFP and RFN which normally would go into a Balun and then to the final antenna.
However I could not find any documentation on how to connect those unbalance RF pins of ATMEL to the SKY IC's standalone pin.
I'm not sure if I would need the balun or not and what would be the recommended matching circuit.
Looking at an Atmel Application Note (AN42140): They are connecting an RCB256RFR2 board (Datasheet) to an SE2431L (Datasheet). There are only one balun between the two of them. No resistors, no capacitors. Is it okay? Connecting them together without any matching circuit?
What do you think?