Ultra-Wideband Rectenna Using Complementary Resonant Structure for Microwave Power Transmission and Energy Harvesting

An ultra-wideband (UWB) rectenna (fractional bandwidth > 100%) using a novel wideband complementary matching stub is proposed for microwave power transmission and energy harvesting. A simple resonant structure, i.e., LC series-parallel resonant circuit, is embedded to the L-shaped complementary matching stub. Due to the unique frequency response of the LC resonant circuit, the proposed matching stub can exhibit open and short circuits as a function of frequency, thereby acting as a complementary matching circuit covering a relatively wide frequency range. Having utilized the proposed matching stub, the nonlinear input impedance of the rectifier can be tuned to conjugately match the antenna impedance throughout the frequency band of interest. Simulated and measured results show that the proposed rectenna has good matching performance (S-11 < -10 dB) and high RF-dc conversion efficiency (>50%) over a relatively wide frequency range from 0.9 to 3 GHz (for GSM, Wi-Fi, and WLAN bands). The maximum conversion efficiency of 73.4% is realized at 3-dBm input power. It is evident that the proposed resonant structurebased matching scheme is a promising and effective solution to facilitate the UWB rectenna design with stably high efficiency over a very wide frequency band.

Automated summary

This paper proposes an ultra-wideband rectenna with a novel wideband complementary matching stub, utilizing an LC series-parallel resonant circuit as the resonant structure for achieving a wide frequency range matching effect. The rectenna demonstrates good matching performance and high RF-dc conversion efficiency over a wide frequency range from 0.9 to 3 GHz, with a maximum efficiency of 73.4% at 3-dBm input power. The resonant structure-based matching scheme is a promising and effective solution for UWB rectenna design with stably high efficiency across a very wide frequency band.