Multi-frequency radar systems for monitoring vital signs

This paper presents a theoretical and experimental analysis of multi-frequency radar systems for monitoring vital signs. The main advantage of using a multi-frequency architecture is the possibility to improve the detection sensitivity of heart beats and breathing rate while cancelling the body movement with signal processing. Simulations were carried out using ADS software for three systems operating at 5.8, 24 and 35 GHz. Different parameters such as antenna gain, mixer conversion loss and LNA gain were considered in the simulations for each system in connection with their system effects. It is shown that by using adequate correlation functions of received signals, it is possible to improve the detection accuracy. Experimental results are presented to validate the analysis and proposed approach.