A 6-10-GHz broadband down-conversion mixer for UWB radio is presented. The mixer is fabricated in the 0.19-μm 1P6M standard CMOS process. The single-port design for the RF, LO and IF ports of the mixer can reduce the complexity of measurement. The broadband mixer only needs a low LO power of -3 dBm which can reduce the effect of LO leakage and DC offset. From 6-10 GHz, the broadband mixer exhibits a maximum conversion gain of 0.8 dB, maximum input P1dB of -4 dBm, LO-RF isolation of about 30 dB, and a DC power consumption of 15.75 mW (without output balun) at VDD =1.5 V, respectively.