There are some threads on eevblog where people add a DIY horn antenna and get about a hundred feet of range for car detection. e.g. [0], video with Doppler audi

There are some threads on eevblog where people add a DIY horn antenna and get about a hundred feet of range for car detection. e.g. [0], video with Doppler audio [1]. [0] https://www.eevblog.com/forum/projects/playing-with-cheap-hb100-doppler-radar-module-for-car-speed/ https://www.eevblog.com/forum/projects/playing-with-cheap-hb... [1] https://www.youtube.com/watch?v=r2NwtRPYWK4 https://www.youtube.com/watch?v=r2NwtRPYWK4