Dual Six-Port based direction-of-arrival detector for FMCW radar tracking in the ISM band at 24GHz

The introduction of the Six-Port receiver as a Direction-of-Arrival (DOA) detector for microwave signals brought new possibilities for countless positioning and tracking techniques thanks to its highly accurate phase measurement capability. Up to now DOA detection of a single frequency continuous wave (CW) signal source has been performed. On the other hand, detection of sources with variable signal frequency is of great interest. In this paper, the DOA detection of an FMCW radar source with a dual Six-Port demonstrator working in the Industrial-Scientific-Medical (ISM) band at 24GHz is presented. Measurement results demonstrate the detection robustness of the system and show frequency dependancy of the detection accuracy.