In this paper, a modified circular microstrip patch antenna is simulated and fabricated for RF energy harvesting applications. Energy harvesting technologies have risen in term of technical developments gradually recently because of the limitation of energy storage and wired power supply. This paper focuses on quad RF energy harvesting in the operating frequency ranges 2.1 GHz, 2.4 GHz, 2.6 GHz and 5.8 GHz emitting from wi-fi, Wimax, LTE, 3G and 4G. The receiving antenna picking up the radio signal in the aforementioned frequencies then converts it from a radiated electromagnetic wave into an alternating signal and, via rectifier, it is converted later into DC voltage. This voltage can be stored inside battery or the load may be fed directly. In this paper, SMD capacitors resistors and Schottky diode model SMS7630-005LF were chosen in the construction of the rectifier circuit due to their low forward voltage between between 0.15 to 0.45 V, fast switching action and small size.