RF Energy Harvesting System And Rectennas

Recent advances in ultra-low power wireless communications and energy-harvesting technologies have made self-sustainable devices feasible. Typically, the major concern for these devices is battery life and replacement. Applying energy harvesting techniques to these devices can significantly extend battery life and sometimes even eliminate the need for a battery. This technique is widely applicable in low power circuits such as wireless sensors. One emerging wireless sensor networks (WSN) application is in agriculture sector, where sensor nodes are deployed in fields to monitor humidity, temperature and soil moisture. Energy supply to such sensors is an issue as they are typically powered by conventional batteries which have a limited lifespan. Cost is often prohibitive when replacing exhausted batteries since the sensor devices need to be unearthed. An attractive solution is to use radio frequency (RF) energy harvesting, in which the radiated RF energy from ambient is extracted and converted into usable energy to power up the sensors. Index Terms — Harvesting energy, Patch antenna, Wireless sensors, Ambient energy , Schottky diode, Resonant circuit. ——————————  ——————————