Microwave Doppler Radar Sensor HB100
Info on amplification: http://www.limpkin.fr/index.php?post/2013/08/09/Making-the-electronics-for-a-%247-USD-doppler-motion-sensor
•Low current consumption
•CW or Pulse operation
•Flat profile
•Long detection range
•Microwave-PIR motion detector
•Speed measurement
•Lighting control