A Broadband Circularly Polarised Slot Antenna for Ambient RF Energy Harvesting Applications

Energy harvesting is a potential source of power for integrating compact low-power and self-sustainable wireless devices in ambient backscatter communication systems and IoT networks. In this paper, an electrically small circularly polarised (CP) slot antenna for harvesting is proposed. The measured CP bandwidth for axial ratio values less than 3 dB is 990 MHz (1.7 GHz to 2.69 GHz), while the measured impedance bandwidth is 1,930 MHz (1.45 GHz to 3.38 GHz). The proposed structure can harvest energy from common radio frequency signal emitters operating in GSM 1800/1900, 3G/LTE 2100, 3G/LTE 2300, 4G/LTE 2500, and 2.4GHz Wi-Fi bands, which makes it an attractive design within energy harvesting technology.