DESIGN OF A DUAL-BAND 900 MHz and 2.4 GHz RF-DC RECTIFIER AND DC-DC BOOSTER FOR ENERGY HARVESTING APPLICATIONS

Abstract

This dissertation focuses on designing and developing a dual-band RF-DC rectifier and DC- DC booster, operating at 900 MHz and 2.4 GHz, for efficient energy harvesting applications. As

the demand for sustainable energy sources grows, converting ambient radio frequency (RF) energy into usable direct current (DC) power offers a promising solution for powering low-power electronic devices such as wireless sensors and Internet of Things (IoT) devices. The proposed system aims to continuously harvest ambient RF energy, providing a reliable and sustainable energy source. The research begins with the design of a dual-band antenna capable of efficiently capturing RF signals at 900 MHz and 2.4 GHz. This antenna is integrated with an RF-DC rectifier circuit

optimized for high conversion efficiency. The rectified DC voltage is then stepped up using a DC- DC booster circuit to ensure sufficient output voltage for various low-power devices.

Component selection is critical, with diodes, capacitors, transformers, and transistors meticulously chosen based on their performance characteristics to maximize efficiency. Advanced simulation tools such as ADS (Advanced Design System) and HFSS (High-Frequency Structure Simulator) are employed to model and optimize the antenna, rectifier, and booster circuits, ensuring optimal performance under different operating conditions. Prototyping and testing validate theoretical designs. Circuits are fabricated on printed circuit boards (PCBs) and assembled for experimental evaluation. An experimental test bench measures the performance of the antenna, rectifier, and booster at various RF input power levels and frequencies. Key performance metrics, including conversion efficiency, output voltage, and power density, are assessed to determine the system's effectiveness.

v Energy storage components, such as supercapacitors, are integrated to enhance the system's capability to provide continuous power. The integrated system's performance is evaluated by powering low-power devices, demonstrating its potential for real-time applications. Data analysis identifies performance bottlenecks, leading to iterative design optimizations to improve overall efficiency and reliability. The optimized rectifier and booster circuits are integrated into a complete RF energy harvesting (RFEH) system in the final phase. This system is tested in real-world scenarios, demonstrating its capability to power wireless sensors and IoT devices using ambient RF energy. The successful implementation underscores its potential to contribute to sustainable and renewable energy solutions, offering a reliable power source for an increasing number of low-power electronic devices. This comprehensive study, encompassing design, simulation, prototyping, testing, and optimization, presents a viable approach to harnessing ambient RF energy for practical applications. The results suggest that dual-band RF energy harvesting is a promising technology for sustainable energy management, providing continuous power to low-power devices and advancing self-sustaining electronic systems.