This work provides a study of Rectenna for Rf Energy Harvesting. Microstrip patch antennas are more suitable for Rf Energy Harvesting. This antenna operates for two distinct frequencies 2.4GHz and 4.4 GHz. The antenna has a compact size of 30×40×1.57𝑚𝑚³ including the ground plane designed on FR-4 substrate. RF to DC conversion circuit with Schottky diode is designed to obtain the DC output. To avoid impedance mismatch a matching circuit using microstrip transmission line is designed and a LC low pass filter is designed to pass only the low desired frequencies is designed. These RF circuits have been simulated using ANSOFT DESIGNER. This can be integrated with Antenna which is designed in HFSS software to achieve usable DC voltage.