In this paper, a DC power management scheme is proposed for efficient battery operation of 60-GHz receivers. It consists of a rectenna and a zero-cross detector. The harmonic rejection capability of a circular sector antenna is used to simplify the rectenna. The zero-cross detector is introduced to increase sensitivity. When the received power density is larger than 0.013 $mW/cm^2$, it can generate enough DC power to activate an RF receiver. Experimental data is used to verify the proposed idea.