A low-voltage low-power 5-GHz divide-by-31/32 prescaler is presented in this paper. An improved phase switching technique is used. By changing the switching direction, an inherently; glitch-free phase switching is achieved without any additional circuit for retiming or synchronization. The phase switching is made between the 45/spl deg/ spaced output phases to further reduce the power consumption and improve the robustness of circuit. The circuit was designed in 0.18 /spl mu/m CMOS process. Simulation shows that it consumes 7.5 mA and 8.2 mA from a single 1.5 V supply with 5 GHz and 8 GHz inputs, respectively.