Analysis and Modeling of Infrared Solar Rectennas

In this paper, an investigation is presented into infrared nanoantennas for solar energy harvesting at 10-μm wavelength, where considerable solar energy is available. These antennas have been modeled using both the integral equation model and the circuit model. The method of moments has been utilized to solve Hallen's and Pocklington's integral equations to find the current distribution over the antenna surface by considering the conductivity and the dielectric properties of gold at this wavelength, as well as its effect on the antenna performance. For verification of the obtained results, this antenna has been simulated using a finite element method-based electromagnetic simulator and both results were found to be consistent. In addition, the metal/insulator/metal (MIM) diode has been studied and its equivalent circuit is presented. Furthermore, a solar rectenna has been constructed by overlapping the antenna arms over a small area to incorporate the MIM diode. The circuit of the solar rectenna, with mathematical expressions for the elements of the equivalent circuit, is demonstrated. Finally, a parametric study into the effect of the MIM diode on the captured voltage is conducted.