In recent years the evolution of wireless communication has made it obligatory to develop compact, low weight antennas. In this research work, a modified inset fed antenna is presented for the Radio Frequency Energy Harvesting (RFEH). The antenna is designed, simulated, and optimized on FR-4 substrate of dielectric constant 4.3, loss tangent 0.025, and height 1.6 mm. The designed antenna operates in WiMAX middle band (3.2 GHz-3.8 GHz). It was found that the proposed antenna exhibits |S11| of −36.94 dB and attains the peak antenna gain and directivity of 2.63 dBi and 5.97 dBi at 3.328 GHz. The feed structure is modified for impedance matching, Voltage Standing Wave Ratio (VSWR) of 1.02, and characteristic impedance Z1,1 of 49.75 ohms is attained at the frequency 3.328 GHz. Characteristics Mode Analysis (CMA) is performed to check the natural resonance of the designed antenna. The simulation results of Computer Simulation Technology (CST) is validated with IE3D software.