Statistical analysis of radiofrequency energy harvester with bandpass filter for ultra‐low power applications

Abstract

AbstractNowadays, radiofrequency (RF) is a vital component of harvesting RF energy from the ambient environment to power ultra‐low‐power applications in wireless communication. This article presents an RF energy harvesting system for a frequency range of (0.58–3 GHz) to harvest RF energy from the ambient source. The system's design consists of four major modules: a coplanar waveguide antenna (CPW), a bandpass filter (BF), an L‐type impedance matching network, and a four‐stage Villard voltage multiplier (VM) circuit. First, A CPW antenna is designed suitably to harvest RF energy from GSM 900/1800, 3G, and Wi‐Fi frequency bands. Next, a BF is designed and simulated in Agilent advanced design system software for the same frequency range to attenuate the RF signals that are not in this specific frequency range. Then, an RF power conditioning circuit prototype comprising an L‐type impedance matching network and a four‐stage Villard VM circuit was integrated and fabricated on an FR4 substrate. The four‐stage rectifier circuit is designed to convert the RF signal into DC output voltage and maximize the output voltage. The performance of the RF energy harvesting system is validated through simulation and measured results. All the RF energy harvesting system elements have been connected, and the prototype is tested at various indoor and outdoor locations of Sri Sivasubramaniya College of Engineering, Chennai, India. It is observed that the prototype system can harvest energy from input power levels as low as −30 dBm. The simulated results of the RF energy harvesting system achieve an output voltage of 2.5 V with a maximum efficiency of 62.5%. The harvested output voltage at a distance of 100 m from the RF cell tower at the indoor location is 59.5 mV and at the outdoor location 271.6 mV. The harvested output voltage is used to energies the ultra‐low‐power applications. Finally, the performance of the RF energy harvesting system is analyzed by statistical techniques. The two types of analysis are Taguchi's method and analysis of variance. The RF energy harvester impact factors are VM and BF. A statistical test (P) is used to determine the significant factors on the RF output voltage.