Ka-band quadrature Doppler radar system with sub-millimeter resolution and sensitivity in measuring periodic movement

In this paper, a 27.6 GHz Ka-band quadrature Doppler radar system is developed to measure the movement amplitude of periodic movement. Experiments were conducted to verify that by increasing the carrier frequency from 5.8 GHz to 27.6 GHz, the resolution can be improved to be in the sub-millimeter range. The relation between the sensitivity-limited detection range and movement amplitude under certain output power was also explored.