A High-Efficiency Rectifying Metasurface With Four Operating Bands

In this letter, a multiband rectifying metasurface is proposed. Two resonant modes are excited through the metasurface structure, and others are introduced by the trapezoidal patch while the resonant intensity is increased. Finally, radio frequency (RF) energy in the quad-band can be captured by the metasurface with the four resonant modes. The rectification efficiency is analyzed at different conditions, and the optimal load and input power level of the system are obtained, which improves the synthetic rectification efficiency of the system. A 6 x 6 array is fabricated and measured. Experimental results show that the proposed rectifying metasurface can capture RF energy at 1.7, 2.4, 3.8, and 5.3 GHz. The peak RF to dc efficiency of the system is 72.1% at the incident power of 0 dBm. Compared with other reports, the proposed one can capture more bands of RF energy with relatively lower incident power level requirements and high efficiency. It may be applied to energy absorption scenarios in RF environments, such as wireless power transmission.