Microcontroller Based Fractional Digital Frequency Synthesizer

A frequency synthesizer is a system that generates a desired frequency from one or more reference frequencies. In this paper, a new simple digital frequency synthesizer is described that allows to generate at the output a signal whose frequency is the sum or difference of the frequencies of 2 input signals divided by an adjustable constant. The paper presents the simulation results of the synthesizer but also the measurement results because the synthesizer was not only simulated but also actually implemented using a microcontroller. The main advantage is that the synthesizer can be created by a program in the microcontroller.