This paper studies a rectifier design for radio frequency energy scavenging at 2.45 Ghz ISM band. The designs of a voltage doubler rectifier that enable RF to DC conversion consists of two units of Schottky diode. This paper also covers the analysis of six zero bias Schottky diodes. The Schottky rectifier is widely used due to their switching speeds that can approach zero time and give very small forward voltage drops. It does allow the circuit to operates at very high frequency and very low power input signals. The rectifying circuit is designed, simulated and measured in this study by using Agilent Advanced Design System (ADS) at 2.45 GHz. The conversion efficiency of proposed rectifier with HSCH-9161 diode gives 31.16%. The rectifier reaches the highest efficiency at 20 dBm input power, which reliable to commercial Wi-Fi access point that operates at 10 to 25 dBm. The higher output voltage is 10.32 V at 20 dBm.