A non-contact vital-signs monitoring sensor system has been designed and tested. The system is assem bled using two antennas instead of using one antenna and a circulator to achieve improved data accuracy with reduced DC offset. The system has been realized using a custom-designed analog baseband signal processing PCB that successfully replaces bulky baseband electronic blocks for system miniaturization. The sensor system was implemented in both single-channel and quadrature receiver configurations with the received signal being demodulated using several different algorithms. The vital-signs data extracted from a quadrature receiver with arctangent demodulation and autocorrelation method is found to be most accurate and reliable, achieving a mean error of +/- 1 beats/min vs. the reference heartbeat signal.