Automotive Short Range Radar Sensor based on the 79GHz Single-Chip ATRX-Transceiver-Family

Today automotive short range radar sensors are only available for the 24GHz band. But in the EU the production of ultra-wideband sensors is limited to 2013. This was the impact to develop a single-chip SiGe RF-transceiver on Infineon’s B7HF200-Process with transition frequencies above 200GHz. The spectral density limit of -9 dBmMHz for the 79GHz-band is much higher than the -41.3 dBmMHz limit for 24GHz. Therefore the built prototype is a FMCW radar and no pulse radar in order to achieve a higher Signal-to-Noise Ratio. The required frequency ramp generation according to the FMCW-Principle is realized without a Phase Locked Loop(PLL), but by controlling digitally the tuning voltage of the VCO with help of a D/A-converter. The non-linearity of the VCO tuning law is compensated by measuring the frequency of the divider signal. Two bistatic transceiver variants have been realized: ATRX2 has one transmitter and three receive channels, while ATRX3 has two switchable transmitters and two receivers. An RF-board has been designed for each chip, where low-cost patch antennas have been applied optimized for a short range system. The angle detection works according to the phase monopulse principle. In the following the configuration for both chips is explained and measurement results are presented in order to demonstrate the angle detection capabilities.