A biased gates passive resistive ring mixer with integrated baluns in 0.18-lm CMOS Taiwan Semiconductor Manufacture Company (TSMC) process is reported. The mixer shows 10% improvement compared with the mixer without biased gates. This is the first circuit report of biased gates resistive ring mixer with integrated baluns. The circuit has been designed and optimized for 2.4 GHz RF frequency and for applying in the contactless heart rate extraction system using microwave Doppler radar. The circuit has the conversion loss of 8.36 dB for 2.4 GHz frequency and indicates 17% improvement compared to the similar types without gate biasing have been reported so far.