A 77-GHz FMCW front-end with FPGA and DSP support

Recent advances in the development of semiconductors allow the realization of low cost 77-GHz radar front-ends suitable for automotive applications. The requirements on the angular resolution often force designers to implement antenna arrays. In the last decade the trend moves towards digital array processing instead of analog beamforming because of the availability of cheap digital signal processors (DSP). In the case of an n-element receive array, the system must be capable of processing n receive channels in parallel resulting in a big amount of data. Field programmable gate arrays (FPGA) deliver the processing power and flexibility to handle the collected data and allow, in conjunction with a DSP, the implementation of sophisticated signal processing algorithms. This paper deals with the implementation of a 77-GHz frequency modulated continuous wave (FMCW) prototype radar system. The system is designed for use in array processing applications, with a maximum of eight parallel receive channels. The functionality of the prototype system is demonstrated in an imaging application. With the help of a portal axis the radar is moved along a synthetic aperture in order to reconstruct the reflectivity map of the imaging area.