A 24 GHz ISM Band Doppler Radar System for Moving Target Sensing

A 24 GHz ISM band Doppler radar system for moving target sensing is presented. The system is comprised of a Doppler radar antenna, transceiver module and display software. High isolation characteristic of the proposed antenna is achieved by inserting a decoupling structure. The simulated -10 dB bandwidth of the proposed antenna is 510 MHz and the simulated isolation between Tx and Rx ports is higher than 36.7 dB over the 24 GHz ISM band. Movement information of an object can be detected by using base-band signals from phase- modulated received wave with proper filtering and decision processing. The proposed system can be a good candidate for contact-free heart rate and respiration rate monitoring in health care applications.