Ultra-wideband rectenna with the dual ground plane for wide dynamic input power and load range

Abstract

ABSTRACT The ultra-wideband rectenna is designed to have a fractional bandwidth of more than 100%, allowing it to work from 1.4 GHz to 5.4 GHz, with a bandwidth of 4 GHz. The proposed design involves a square patch antenna that incorporates an inverted L-slot and utilises dual ground planes in the form of rectangular and semi-octagonal shapes. The intended rectenna simultaneously harvests energy from various frequency bands, including GSM 1800 MHz, UTMS 2100 MHz, ISM 2450 MHz, 2800 MHz, and 3600 MHz. The proposed rectifier circuit incorporates three impedance-matching (IM) branches, which effectively mitigate the nonlinear attributes of the rectifier system and ensure favourable IM across a broad spectrum of frequencies. The DC combining technique is employed to attain favourable conversion efficiency. The CE in the GSM 1800 MHz band was measured to be 74%. The CE in the UTMS 2100 MHz band was measured to be 66%. In the ISM2450 MHz frequency band, a CE of 76% was measured. The CE in the 2800 MHz frequency band was determined to be 67.5%. At 3600 MHz, the measured CE is recorded as 67%. The obtained optimal load value is 470 Ω and it provides more than 65% conversion efficiency (CE) at all the intended frequency bands. The proposed rectenna demonstrates an CE exceeding 50% across the entire range of input power level (IPL) variations from 0 to 11 dBm. Furthermore, it achieves an efficiency surpassing 60% when subjected to load variations ranging from 270 Ω to 750 Ω.