Millimeter-wave Doppler velocimetry for low-velocity measurement

A new millimeter-wave Doppler velocimeter operating at 35.6 GHz has been developed, using MICs and MMICs, and demonstrated as a sensor for measuring low velocity. The Doppler frequency was determined by applying linear regression on the phase sampled within only fractions of the period of the Doppler frequency. A digital quadrature mixer was configured by employing quadrature-sampling signal processing technique for phase detection. Experiments were performed in laboratory for moving target on commercial conveyor. The sensor was able to measure speed as low as 27.7 mm/s, corresponding to 6.6 Hz in Doppler frequency, with an estimated velocity resolution of 2.7 mm/s.