A GaAs MMIC Doppler Sensor for Automotive Applications

To automate the driving of terrestrial vehicles, it is necessary to determine with the highest accuracy instantaneous information about the motion of the vehicles, especially the values of the instantaneous speed and of the distance covered by the mobile. A full integrated microwave Doppler radar including a GaAs MMIC microwave head with a MESFET oscillator and a MESFET mixer, and using a plane printed antenna is described. This system which was tested in laboratory and also on vehicles can be used for a lot of other applications such as antilocking, antiskating systems, active suspensions, automatic tolls, and communications between vehicles or between a vehicle and the ground.