Non-contact measurement of rotational movement using miniature Doppler radar

In this paper, the Doppler radar non-contact sensing technology is extended from measurement of one dimensional movement to a practical application in measuring rotational movement. Both simulation and experiment show that Doppler radar can detect the speed of angular movement such as electric fans or motor rotation. It has been shown that in Doppler radar based non-contact rotational movement measurement, the baseband output will have a dominant fundamental frequency that is multiple of the rotation frequency that depends on the structure of reflectors on the target.