A fully differential low-power down-conversion mixer using a TSMC 0.18-μm CMOS process is presented in this paper. The proposed mixer is based on a folded double-balanced Gilbert cell topology that enhances conversion gain and reduces power dissipation. Though, this mixer is designed for 5.8 GHz ISM band applications, but at 0.5-7.5 GHz, the proposed mixer exhibits a maximum conversion gain of 12dB, maximum IIP3 of -2.5 dBm, maximum input 1-dB compression point of -13 dBm, the minimum DSB noise figure of 9.2 dB and a dc power consumption of 2.52 mW at 1.8 V power supply. Also, this circuit architecture increases port-to-port isolations to above 140 dB. Moreover this mixer is suitable for broadband applications.