Microwave Presence detector works using Doppler Effect

https://www.electronics-lab.com/microwave-presence-detector-works-using-doppler-effect/

It detects stationary and moving people just like a PIR, but it can do that also behind doors and thin walls, by taking advantage of the Doppler effect. By Boris Landoni @ open-electronics.org: The detection of people, animals and hot bodies in general has been done for years using passive infrared radars, also known as […]