A novel RF energy harvesting cube based on air dielectric antenna arrays

摘要

In this article, a new 2x2 circular microstrip antenna array with air dielectric layer for ambient RF energy harvesting has been proposed. Two pairs of arc-shaped slots located close to the boundary of the circular microstrip patch have been designed for achieving dual-band response and extending the frequency bandwidth. The antenna has a frequency bandwidth from 1.85 to 1.93GHz and from 2.0 to 2.1GHz which can cover GSM-1800 and UMTS-2100 bands. At the frequency of 1.89 and 2.05GHz, the measured gain is 5.3 and 6.6dBi, respectively, and high gain of 3.8-9.3dBi has been achieved over the whole band. Also, a broadband rectifier that can cover all the bandwidths of the antenna array is designed for the rectenna, which has the maximum rectifying efficiency of 53.6%. Finally, a cube device formed of four antenna and four rectifiers is designed to harvest RF energy, whose maximum output DC voltage is 2.3 V and the maximum output power is 4 mW that can drive four LEDs and an electronic watch.