I am looking for ways to improve reception between two of my devices. The communicate on the 868 MHz ISM band with a 2-GFSK modulation.
The problem is that one of them is heavily shielded by metal (and I cannot change that) so reception is pretty bad.
I am using the CC1310 from TI and they recommend their CC1190 as a front-end to improve performance. In the reference schematic of the LAUNCHXL-CC13-90EU which uses a CC1310 and a CC1190 they added a SAW filter (B3725 from Qualcomm) between the CC1310 and the CC1190 RF front-end. I suppose to improve selectivity.
My question is: When do you use SAW filters? I can see that they improve selectivity a lot, but they also add insertion loss. So the overall signal is even weaker. Does it only help when there is a lot of noise on nearby frequencies or does a filter like that improve always performance?