Measurement of the rotational sense and velocity of an object using OAM wave in the radio-frequency band
A method is presented to improve the determination of the rotational velocity of an on-axis spinning object. It uses the Orbital Angular Momentum (OAM) of an electromagnetic wave at 2.47 GHz, and measures the rotational Doppler frequency shift of a reflected wave. From this shift, the rotational velocity and the direction of rotation can be directly estimated with very good accuracy.