Auxiliary ring resonator for local field enhancement in solar rectennas

In this paper, a study is conducted into using an auxiliary ring to enhance the captured (confined) electric field at the gap of dipole nanoantenna for the use in solar rectennas. The system is constructed of main resonator, the dipole antenna, and a booster resonator, the auxiliary ring. It is generally accepted that the dipole antenna captures limited amount of solar radiation. Thus, boosting its performance with an additional resonant element will increase the captured electric field at its gap, and hence, increase the conversion efficiency of the solar rectenna. The designed structure has been simulated using FEM-based software. The results showed that the performance of the rectenna can be improved by adding an additional resonator. This can be achieved by exploiting the mutual coupling between the two elements. Furthermore, the effect of the distance between the ring and the dipole has been studied. Finally, different shapes of the ring have been used and it is found that the circular ring has the best performance.