Improving the directivity of the plasmonic sectoral horn nanoantenna using lens in its aperture

Horn antennas can result in good impedance matching between the waveguide and free space due to the gradual increase in the aperture size. In this paper, a novel plasmonic sectoral horn nanoantenna based on using lens in the aperture is proposed. It is investigated that in addition to improvement of the directivity, the reflection coefficient is also reduced using the proper lens structure. The maximum directivity improvement is about 2 dBi compared to the structure without lens. Also, it is shown that the radiation pattern can be controlled by utilizing electro-optical material as the lens