Gain improvement for conventional rectangular horn antenna with additional two-layer wire medium structure

This paper presents the technique of the metamaterial on a two-layer wire medium structure for gain improvement of a conventional rectangular horn antenna without its construction enlargement. From our study, we find that the proper metamaterial structure is capable to enhance the gain of the antenna as the additional resonant circuit, exhibit bandgap characteristics at the operating frequency, installed in front of the antenna. This is due to the proper metamaterial exhibits frequency bandpass and bandstop that can block the surface wave excitation in the operating frequency range of antennas. The gain enhancement synthesis method for the proper metamaterial, which is to transfer the electromagnetic fields from aperture of a horn radiated simultaneously through this metamaterial, so that the phases of electromagnetic wave transmission are equal resulting in ultimate resonance The proper metamaterial that is presented by using a two-layer wire medium structure, the 3D volumetric structure. The proposed technique has the advantages of low profile, low cost, and light weight. The antenna characteristics such as reflected power (S11), radiation patterns, and gain are simulated by using the simulation software. From our simulation results, we note that the S11of this proposed antenna (at -10dB) covered 8-12 GHz, which was wide enough and could be well suitable for application for X-band and I-band following the IEEE and the ITU standards, respectively. The gain at the operating frequency of 10 GHz is 24 dBi, which higher than the gain of a basic rectangular horn antenna around 6dBi with adding only one appropriated metamaterials on a two-layer wire medium structure.