for help: Bias condition of LO switch pair of Gilbert mixer

hi, Does anybody can tell me what bias conditon of the LO switchpair should be ? Some body tell me that the LO switch pair should be biased at Vgs ≈Vth, and smaller than Vth. Do you think it is right or not?
Thks.

Vgs≈Vth or not is detemined by the MOS size and current. NOT the bisa condition.

In my opinion, you should quarantee the Vds >Vgs.