Introduction

Radikant-SA-C is RF Signal Analyzer written in C. Designed for simplicity and ease of build. It is meant as an easy depedenency to be used for build your own spectral analaysis applications. I used a modified version of MicroUI to support graphing, waterfall and IQ constelation. For testing with an RTL SDR i used libsdr to get IQ data. And use my own Radikant-FFT-C for Fast Fourier Transform (FFT)

Figure 1 - Listening 101.2 Mhz

In Figure 1 the software is analyzing 101.2 Mhz which in the Netherlands is Sky-Radio. I set the RTL SDR to 300 Khz bandwidth, and in the waterfall the FM modulation is visisble. The IQ Constelation shows a rotating donut which alligns with FM modulation.