Active Reflector Tag for Millimeter Wave Harmonic Radar at 61/122 GHz ISM Band Based on 130 nm-BiCMOS SiGe:C Technology

This paper presents a nonlinear reflector suitable for operation in a harmonic radar at 61/122 GHz. The active tag is based on a MMIC fabricated in a modern 130 nm SiGe:C BiCMOS technology. The challenges for high dynamic range measurements are pointed out to undermine the advantages of active tags at this frequency range. On the MMIC gain stages and a frequency doubler for the frequency translation are implemented. Measurements are presented to characterize the conversion gain of the MMIC itself and the entire tag respectively. The impulse response of the tag is measured by realizing the FMCW transceiver with a VNA. For a 2 GHz bandwidth sweep the tag shows a spatial resolution of 9.8 cm. It consumes 40mA at a 3.3V supply. With these characteristics the tag enables harmonic radar applications in the millimeter wave range.