Integrated 3D Tag Localization Using Multi-Channel Harmonic Radar in the 61/122 GHz ISM Band

This work presents an integrated 3D localization system that employs a harmonic radar operating in the 61/122-GHz ISM bands. Two custom MMICs, designed in 130-nm SiGe BiCMOS technology, implement the transceiver and active harmonic tag. The system uses multilateration with four frontends integrated on a single backend, enabling fast sequential distance measurements on an FPGA-based platform. Experimental results show sub-millimeter accuracy along the range axis and an <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$x y$</tex>-plane standard deviation of 4.4 mm with a maximum error of 2.2 cm, highlighting the potential for efficient and precise tracking of active harmonic tags in complex environments.