RF Switch-Based Radar Systems for Simultaneous Multi-Target and Multi-Direction Vital Sign Detection

Abstract

This thesis proposes a RF switch-based radar system for multi-target and multi-direction vital signs detection simultaneously Since continuous wave (CW) radar does not have the ability of range resolution the signals of multiple reflections are mixed together and the phase information cannot be distinguished In contrast frequency modulation continuous wave (FMCW) radar has suitable range resolution and relatively simple system architecture Therefore FMCW radar has the capabilities of multi-target monitoring and distance information We use FMCW radar to detect the vital signs of the two targets in various distance simultaneously By using RF switch as a multiplexer we can detect multidirection signal in a transceiver instead of multiple radar system Moreover switch has the function of mixing By proposed RF switch-based radar system we practice low-IF architecture for multi-direction vital signs detection simultaneously In terms of demodulation heart rate (HR) is susceptible to the harmonic of respiratory rate (RR) Therefore we use ensemble empirical mode decomposition (EEMD) algorithm to extract the intrinsic mode functions of RR and HR Experiments show that we can improve signal-to-noise ratio (SNR) and accuracy significantly using this algorithm And the vital sign errors of multiple targets are below 3% averagely

Date of Award	2019
Original language	English
Supervisor	Chin-Lung Yang (Supervisor)