This post explains for the semiconductor RDA1846S.
The Part Number is RDA1846S.
The function of this semiconductor is SINGLE CHIP TRANSCEIVER.
Manufacturers : RDA
Preview images :
The RDA1846S has a powerful digital signal processor, which makes it have optimum voice quality, flexible function options, and robust performance under varying reception conditions.
The transceiver uses the CMOS process with a package size of 5x5mm. By virtue of its high integration, it requires the least external components and eliminates the complicated design of sensitive RF circuits on PCB.[…]