Efficient integrated 5 × 2 rectenna array for low RF energy recovery

Abstract

The present study provides a series–parallel combination of connected rectenna arrays using SMS7621-001LF Skyworks Schottky diodes at 5.8 GHz to harvest wireless systems’ power. The proposed configuration is an array of patch antennae with a rectifying circuit, while in the array connection, the rectenna system works with the most optimal conversion efficiency. Based on the results obtained from the fabricated proposed rectenna’s optimal efficiency, an RF power density ranging from 30 to 160 µW/cm2 has been obtained. Also, the conversion efficiency of RF-to-DC power is more than 77%. The measured output DC voltage of 10 elements in a parallel-series connection is 9.1 V, and their output current has been measured at 130 mA. The highest power conversion efficiency in the proposed rectenna system is 75.2 at a power density of 90 µW/cm2. The conversion efficiency is almost constant in this rectenna as the number of elements increases. Also, during this experiment, it was proven that the addition of a rectifier to the receiving antenna has not only a very small effect on the radiation efficiency but also has not much effect on the features of the main beam of the antenna system. The prototype unit cell rectenna and array are fabricated, and their performance is validated using measurements.