Characteristics of a V-shaped rectenna for 28.3 THz energy harvesting

Abstract

A rectenna structure based on a potentially printable V-shaped nanoantenna (VSNA) design is introduced and numerically analyzed. The characteristics of the VSNA structure have been investigated through the electric field enhancement and radiation efficiency used as figures of merit to evaluate its performance. A comparative study has been performed between the VSNA and a conventional dipole THz antenna based on the same dimension constraints. Therefore, the VSNA has shown better and more localized field enhancement at the arm tips. Furthermore, an optimization process has been carried out to maximize the electric field at the resonance frequency (28.3 THz). The suggested design offers more than 300% improvement in electric field confinement compared to a conventional dipole antenna at 28.3 THz. This enhancement is attributed to the tip-to-tip geometry, leading to a highly localized field at the tip. Further, the optimized VSNA design is employed to form a rectenna structure by inserting an ultra-thin insulator layer between the tips of the antenna arms. The reported rectenna structure increases total efficiency from 11 to 26.58%, with a 141% improvement over previously reported work. Beyond the potentialities presented by the proposed design, its simplicity makes it manufacturable for efficient energy harvesting applications. Finally, the metal–insulator–metal (MIM) diode rectification capabilities have been investigated through a quantum mechanical simulator (built on MATLAB software) with aluminum oxide (Al₂O₃) as an insulator sandwiched between gold (Au) and silver (Ag). The suggested MIM diode (Au/Al₂O₃/Ag) offers a zero–bias responsivity of 0.93 A/W, which is higher than the previous work based on Al₂O₃ which was 0.5 A/W.