I am trying to use RDA5807M to build a radio. My circuit is basically the same as the reference design in data sheet.
I know the design uses the GND of earphone as antenna. But I don't understand the function of F1, F2, C1 and L1. I chooses to remove them from my circuit and the circuit works well. What if I put them back? Will the antenna work more efficiently?
Another question, why the LC tank consists of C1 and L1 is 107MHZ?