Radar system for an anti-collision system for a vehicle

摘要

A pair of antennas mounted on a vehicle receive an echo wave reflected from an obstacle to produce a pair of Doppler signals, the variation of the phase difference of which is used to indicate the direction of the relative movement of the obstacle. The phase difference also represents the difference in propagation lines and is proportional to the relative angular displacement of the obstacle so the rate of variation of relative angular displacement is detectable because the increase and decrease of phase difference negate each other.