This paper demonstrates that using sub-sampling mixer topology can be the right choice to implement a millimeter-wave (mmW) receiver. In a 77 GHz radar receiver, it allows to reduce the burden of a 77 GHz LO distribution chain, in term of area and consumption, while preserving RF performances. Demonstration is done from two topologies of ×3 sub-sampling mixers implemented in 28-nm FD-SOI CMOS technology. The best proposed passive mixer exhibits a-2.1 dB conversion gain (Gcv), a 1dB input-referred compression power (ICP1dB) of +3.5 dBm, and a 16.8 dB Single Side Band Noise Figure (NFSSB). The mixer LO signal shaping consumption is 32 mW on a 1.2 V supply while the passive mixer core does not require any DC power.