A review of rectenna models for electromagnetic energy harvesting

Purpose: Distributed wireless sensor networks (DWSNs) are applied in a variety of applications that can enhance the quality of human life. Batteries are the predominant source of energy in DWSNs. One of the key obstacles in the adoption of DWSNs technology is the limited lifetime of batteries in microsensors. Recharging or replacing depleted batteries can significantly increase costs in DWSNs. The purpose of this paper is to address, through a thorough review, this power challenge in DWSNs and to evaluate a 16-element equiangular spiral rectenna to harvest ambient microwave energy in real-life scenarios to supply indoor DWSNs. Design/methodology/approach: The paper focuses on the practical implementation of a rectenna that can be used in electromagnetic energy harvesting. The design and measurement of the rectenna follows a broad overview of rectenna designs reported in the literature. Findings: The paper concludes that the 16-element equiangular spiral rectenna has the potential to generate power that enables long periods of operation of the DWSNs without human intervention in the power management process, thus reducing maintenance and administration costs. Originality/value: Research into electromagnetic power harvesting is very limited in the South African context. The paper presents a concise overview of existing power harvesting techniques that will benefit novice researchers in the field of electromagnetic energy harvesting. It concludes with the performance characterisation of a spiral array rectenna.