A multistatic microwave radar sensor for short range anticollision warning

An adequate radar technology for the detection and localization of obstacles before, behind and on the sides of a moving car is of primary importance to realize on-board devices able to perform different tasks such as parking, stop and go, and pre-alarm of the frontal air-bags. In these situations, the radar must acquire the position of the obstacles located at short distances from the car. This acquisition must be carried out with high radial and angular resolution; the former needs large radio frequency bandwidth, the latter requires large antennas and this means that the investigation area of the radar is certainly in the near field of the antenna. It is for this reason that traditional anti-collision systems based on phase array antennas prove to be unsuited to perform these tasks in the short range. The solution that we are proposing is based on several independent microwave radar sensors with wide angle of view connected to a central processing unit able to define the position and the relative velocity of the nearest obstacles. This prototype works in the 13.4-14 GHz frequency range at low power (16 dBm cirp) in accordance with the ETSI and CEPT/ERC Recommendations and it has been realized with microstrip technology so that thanks to its reduced size each device can be embedded easily in a bumper.