A Broadband CPW Fractal Antenna for RF Energy Harvesting

摘要

A novel broadband CPW-fed 2-iteration fractal antenna based on the circular patch and the equilateral triangle slot is designed for RF energy harvesting. The simulated and measured results show that the proposed antenna offers an impedance bandwidth of 162% from 0.88 to 8.45 GHz and a peak gain of 8.7 dBi. Afterwards, the single-stage voltage multiplier rectifier with a T shape LC matching network to reduce the reflection losses is used to realize RF-toDC conversion in energy harvesting; here, it is also integrated with the fractal antenna to form the rectenna. Accumulating RF power from 2G (GSM), 3G (the third generation), 4G-LTE and WLAN frequency-bands, the measured results across an optimized load resistor of 4.7-kO show that the maximum rectenna efficiency is 51.8%, 46.1% and 45.08% at the center frequency of 2.4 GHz, 2.1 GHz and 1.9 GHz, respectively. Additionally, the measured peak conversion efficiency of the system is 24.03% at 2.4 GHz.