Multi-Radar Near-Field System Employing Multi-Band Non-Interleaved Metasurface for Enhanced Bio-Sensing

Multi-radar sensing significantly enhances accuracy and sensitivity in non-invasive, real-time wearable health monitoring. This paper introduces a system that employs near-field focusing of radar interactions on human skin at various locations, with the multi-radar setup gathering data from multiple points to enhance detection capabilities. A multi-band non-interleaved metasurface is integrated into this system, improving the detection of physiological parameters, including the identification of human blood abnormalities. The methodology utilizes discrete zones of a transmissive metasurface, each composed of phase-synthesized arrays. These zones serve as low-profile impedance matching networks, optimized for specific frequencies within the 58 to 63 GHz millimeter-wave radar range, thereby increasing efficiency through higher absorbed power density at different frequencies, which also enables varied penetration depths into human skin. Analysis using a customized phantom, closely resembling human skin, demonstrates significant increases in near-field absorbed power density: over 11 dB at 60 GHz and 2 mm penetration depth, over 17 dB at 58 GHz, and 9 dB at 61 GHz at the same depth.