A wideband slot antenna for RF energy harvesting

This study details the design, simulation, and experimental evaluation of a compact wideband slot antenna tailored for ambient radio frequency energy harvesting (RFEH) applications. The design incorporates an inverted T-shaped stub along with dual E-shaped stubs embedded within a rectangular slot, excited by an extended T-shaped microstrip feed line. The antenna, fabricated on an FR-4 substrate with a relative permittivity of 4.4, exhibits simulated and measured impedance bandwidth (BW) of 1.10 GHz and 1.05 GHz ranging from 0.87 to 1.97 GHz and 0.84 to 1.89 GHz both defined at the - 10 dB respectively. It attains a peak realized gain of simulated (measured) 4.97 dBi (4.86 dBi), all within a compact footprint of 0.59[Formula: see text] × 0.44[Formula: see text]. Parametric analysis and comparative simulations were conducted to validate the effectiveness of the proposed design. Measurements obtained from experiments carried out in an anechoic chamber show a high level of consistency with the simulated data, reinforcing the accuracy and reliability of the simulation model. Integrating the antenna with a high-efficiency rectifier circuit results in effective power conversion under ambient environmental conditions, confirming its viability for supplying energy to low-power IoT sensor nodes. The proposed design achieves an effective compromise between compactness, wideband capability, and energy harvesting efficiency.