Understanding how encoding and decoding in FM radio works

contact@julhcam.eu (JulHCam) — Tue, 14 Jul 2026 00:00:00 +0000

One day, while listening to the radio I wondered, “how does FM radio work?”. I had the intuition that you change the frequency of the carrier based on the amplitude of your encoded signal, but how does that actually work mathematically? While searching online I found a great article by Niklas Oberhuber titled “How FM Radio Works”, which explained just that, and even simulated the operation of two radio stations and how depending on the settings used they can interfere with eachother. Wanting to learn more, I contacted Niklas and he very kindly sent me the code files he used to generate the results in that post. I’ve been looking through the code, reading more about the maths and I think I finally have a rough understanding of how FM radio works from a mathematical perspective. So, in this post I will explain how FM encoding and decoding works but not discussing the hardware that actually does e.g. the decoding in a handheld FM radio like the one I own. Perhaps for a future article as that’s a whole different pickle with which I don’t yet feel as comfortable with as with the maths!

Rewriting my personal website

contact@julhcam.eu (JulHCam) — Sat, 04 Jul 2026 00:00:00 +0000

When I wrote my old website, it was (I think) the winter holidays of 2023. My knowledge of many things related to the web was quite limited, yet I launched myself into making a Gatsby website inspired by the design of castel.dev (checkout his posts if you like LaTeX!). I was happy with the end result, but it was convoluted and full of code that I didn’t understand. The result of that is that updates were uncommon as everytime I had to remind myself of how the page was setup and how to introduce new content into it. Then I started to stumble into posts that said Gastby was not in a good state and although I don’t claim to understand exactly what happened, it wasn’t a good sign.