24 GHz Radar Sensor integrates Patch Antenna and Frontend Module in single Multilayer LTCC Substrate

The authors from IMST and DuPont have developed in joint project a RADAR demonstrator operating in the 24 GHz band. The sensor is designed to be used in vehicles as driver assistance system. FMCW method is utilized to measure distances up to 30 m or even more and velocity of obstacles around the car. Especially safety enhancement systems like collision warning and mitigation but also comfort features can be realized. Moreover, the sensor is capable to be integrated in manifold industrial applications where distance and velocity have to be determined with high precision. Another interesting field of application is the monitoring of buildings and real estates, because the module concept is qualified for the free 24 GHz ISM band, too. The main focus of the development is directed towards the reduction of costs in comparison with conventional sensors. Hybrid circuit technology using 5-layer LTCC tape 951 from DuPont Microcircuit Materials has been realized. The patch-antenna is printed on one side of the multilayer ceramic, while the RF frontend has been integrated on the opposite side. The HF part of the demonstrator is as small as 34 mm x 21 mm. Signal conversion and signal processing are executed on an external board with USB interface to a PC. A software with graphical user interface allows the setting of sensor and evaluation parameters.