A Novel Miniaturized Broadband Pentaflake Fractal Based Integrated Rectenna for Ambient RF Energy Harvesting for Smart City Applications

This article presents a novel, ultra‐compact pentaflake fractal‐based rectenna designed for broadband ambient RF energy harvesting. A miniaturized monopole patch is developed by etching a three‐iteration pentaflake fractal on the radiating element, resulting in enhanced bandwidth and improved impedance matching. Additionally, a Hilbert fractal slot integrated into the ground plane further increases the antenna's bandwidth and gain. The antenna operates across a wide frequency range of 3.8–7.4 GHz, offering an impedance bandwidth of 3.7 GHz and a peak gain of 5.7 dBi. To ensure compactness and low‐loss operation, a series‐pair voltage doubler rectifier is integrated on the same substrate. The proposed rectenna achieves simulated and measured power conversion efficiencies of 65.88% and 64.67%, respectively, at an input power of 11 dBm, producing output voltages of 2.31 V and 2.23 V. By integrating both the antenna and rectifier on a single substrate, energy loss is minimized and overall performance is enhanced. The strong agreement between simulated and experimental results confirms the reliability of the design. To the authors' knowledge, this is the smallest integrated rectenna reported to date, offering compact size, broadband characteristics, and high efficiency for practical wireless energy‐harvesting applications, including IoT devices, sensor nodes, and wearable electronics.