Compact Dual-Band Rectenna on a New Paper Substrate Based on Air-Filled Technology

This paper presents a compact paper-based rectenna with dual frequency operation. The rectenna is composed of a microstrip antenna designed on paper, in which an air gap is introduced between the patch and the ground plane to overcome the low-thickness and high-loss characteristics of the conventional paper substrate. This allows the microstrip antenna to reach a high radiation efficiency and a large bandwidth. Additionally, a miniaturization technique is utilized to reduce the antenna dimensions imposed by the low permittivity of the air. The absence of matching network between the antenna and the rectifier ensures a very compact size as well as limited insertion losses at the rectifier level and results in a high RF -DC conversion efficiency in the two frequency bands 1.8 and 2.4 GHz. The rectenna prototype shows experimental conversion efficiencies of 25 and 19 % at 1 μW/cm
²
and 55 and 44 % at 10 μW/cm
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at 1.8 and 2.45 GHz, respectively, corresponding to output DC voltages of 208, 190 and 933 and 923 mV. Furthermore, output DC voltages of 93 and 550 mV are maintained over the band 1.75-2.6 GHz at 1 and 10 μW/cm
²
respectively. The rectenna prototype features a weight of 1.5 g and dimensions of 0.21 λox0.21λox0.06λo.