An FM transmitter is one of the most popular devices between electronic hobbyist, professionals and even non-technical people. In this article, we gonna learn to how to build an easy, stable and digitally controllable FM transmitter.

For this design, I have selected the VMR6512 module which truly is like a full RF block on a chip!. It eliminates all essential circuitry for a basic FM transmitter such as inductors and trimmers. According to the VMR6512 datasheet: “VMR6512 is a highly integrated FM audio signal transmitter module. It integrates advanced digital signal processor (DSP), frequency synthesizer、RF power amplifier and matching network. So it can realize FM audio modulation without any external components. VMR6512 can also achieve broadcast quality sound by using digital pre-emphasis, digital filtering, automatic gain control, and digital frequency control technologies.“

The operation frequency range is between 88.0MHz to 108.0MHz. the figure-1 shows the schematic diagram of the transmitter.

Figure-1

The schematic diagram of the FM transmitter

More details please check here https://www.pcbway.com/blog/technology/How_to_build_a_digital_coil_less__100KHz_step_size__FM_transmitter.html