Ultra-Wideband FMCW Radar with Over 40GHz Bandwidth Below 60GHz for High Spatial Resolution in SiGe BiCMOS
Fields of application like industrial measurement, security, and material characterization with harsh demands for high spatial resolution require FMCW radar systems with high absolute bandwidth. Hereby, close adjacent targets can be distinguished from each other. Usually those systems are designed at very high frequencies around 100GHz and above because here, sensors with high bandwidth can be designed with less effort but signal handling, antenna design and high output power is more difficult and harder to achieve at those frequencies. In this work, a modern SiGe BiCMOS process was used to develop an ultra-wideband (UWB) bistatic FMCW radar MMIC with over 40 GHz continuous bandwidth below 60 GHz. This MMIC is the key component of the presented ultra-wideband FMCW radar system. The high bandwidth is generated by down-converting two high-frequency VCOs at around 100GHz but merely the down-converted signal below 60 GHz of both VCOs which is easier to handle leaves the MMIC. The output signal provides a frequency range which corresponds to the sum of the bandwidths of both VCOs. This leads to a radar system that achieves ultra-wide continuous bandwidth at moderate frequencies for high spatial resolution.