Review on Advanced Short-Range Multimode Continuous-Wave Radar Architectures for Healthcare Applications

Short-range radar systems are noncontact devices that are attracting much attention from the RF/microwave community. In particular, they are being applied in healthcare contexts, ranging from hospital to indoor and outdoor environments, e.g., for monitoring of vital signs and/or tracking of human activities. This article reviews the standard architectures for short-range biomedical radars and presents recently proposed hybrid schemes, which combine different operation modes, leading to performance improvement. Specifically, hybridizations associated with Doppler, frequency-modulated continuous-wave, and tone-ranging-based schemes are provided from theoretical and simulation viewpoints. Some experiments on vital-sign monitoring and human-aware localization are also reported.