Radio frequency energy harvesting is an emerging technology that enables to drive the next generation of WSN nodes and different sensors with environmental & wireless sensor networks friendly alternative energy sources. this reduce reinstallation, maintenance, and battery replacement cost. also in some environments practically impossible to access and replace battery. Throught this study, first radio frequency energy analysis is carried out at different cellular, ISM and cordless phone bands on Bahir Dar to select better energy available radio frequency bands for the harvester. Moreover the paper presents the design and simulation of low input power aware (low return loss) and reactive impedance matching circuit. Then design low forward biased voltage, fast switching microwave rectifying circuit to collect from 1.8 GHz, 2.1 GHz and 2.4 GHz frequencies. This band was chosen due to they have high RF signal power availability bands in the indoor and outdoor environment. Advanced Design System (ADS) software is used for designing the harvester. The simulated results prove that the maximum output voltage is 2.52V and 3.69V with an input power of 0dBm and 3.16dBm respectively for the single stage HSMS-2852 diode. We can also got 395mV output voltage for the -15dBm input radio frequency power. Moreover, the rectifier offer efficiency of 40-49% for the input power of 0 dBm respectively, which can easily power up wireless sensor networks (WSN) and other small devices sufficiently. The harvester has small size, low cost, low forward voltage and high efficiency. Generally we designed the harvester in our country context (interms of high power RF available bands, cost and sensitivity of the system). additionally it is portable.