Newer version in this post - <a href="http://hforsten.com/third-version-of-homemade-6-ghz-fmcw-radar.html" rel="nofollow">http://hforsten.com/third-version-of-homemade-6-ghz-fmcw-rad...</a><p>An interesting application of CW radar - <a href="http://hforsten.com/heartbeat-detection-with-radar.html" rel="nofollow">http://hforsten.com/heartbeat-detection-with-radar.html</a><p>At 45 years old I feel like I've learned quite a bit, but when I read stuff like this I wonder if there are enough years left in my life to learn what to takes to put something like this together.<p>I will say that the little CW doppler radar boards are fun to tinker with. You can get them on amazon for <$10 shipped, power them with 5 volts and just wire the output to a microphone jack.<p><a href="https://www.amazon.com/SMAKN-Microwave-10-525GHz-Doppler-Detector/dp/B00FFW4AZ4" rel="nofollow">https://www.amazon.com/SMAKN-Microwave-10-525GHz-Doppler-Det...</a><p>This is what a coin toss over a 10GHz doppler device sounds like: <a href="https://www.youtube.com/watch?v=8riretP8ylE" rel="nofollow">https://www.youtube.com/watch?v=8riretP8ylE</a>