A 2.45 GHz Frequency-Selective Rectenna for Wireless Energy Harvesting

Abstract

As the emphasis placed on renewable energies has grown over recent years, a necessity for innovative methods of providing alternative energy sources has emerged. With most modern communication systems utilizing radio transmissions, signi cant amounts of broadcasted radio emissions are regularly wasted. Implementing radio energy scavenging systems in such areas provides an opportunity to save otherwise wasted energy in these environments. Providing a novel wireless energy scavenging system, this paper presents a linearly polarized rectenna using a two diode system for the recti cation circuit. The rectenna uses a dipole square patch antenna with a frequency-selective surface (FSS), which behaves as a lter while also reducing the size of the rectenna. Made using multiple layers, the rectenna consists of two Rogers 5880 Duroid substrates 508 m (20 mil) in thickness with an e ective permittivity of 2.2 and a Rohacell foam spacer 5 mm in thickness with an e ective permittivity of 1. This dual-diode FSS rectenna reaches a RF-to-DC conversion e ciency of 79% at 2.45 GHz. The use of a FSS replaces the traditional transmission line lter used in most rectenna systems while improving the matching of the antenna and reducing the surface area of the rectenna. The rectenna is linearly polarized with a broad angle of energy reception for absorption of ambient radio waves within the ISM band and is well-suited for energy harvesting applications.