FYI, there's an updated version of this video/concept here:    • GRCon22 - Kuiper Linux Distro - Simpl...  

Or, you can watch this video! It was a few years ago, and was my first attempt at building a simple FMCW X band radar system. I'm using the ADF4159 to generate a triangle shaped linear frequency chirp. Then transmit with a horn antenna. The echo is received by a 4 element ADAR1000 array and digitized by the ADALM Pluto in GNU Radio. This is a very simple setup, with no digital processing--just so I can play with the basics.