Search

Due to the properties of inverse refraction, the metamaterials can focus the incident wave and can be used as a lens for high directive antennas. For this purpose, in this study, initially, a metamaterial unit cell is designed to exhibit metamaterial feature at 12 GHz and converted into a periodic layer. The reference antenna and the proposed metamaterial layers are simulated and fabricated. It is observed that the directivity of the reference antenna is increased by 2.74 dB with one layer of the proposed metalayer according to the measurement results. Finally, a double lens layer is used and an increase of 4.08 dB is observed. In the literature, the dimensions of metalayers, that is, used to achieve directivity enhancement, are larger than the patch size, but in this study we achieve a significant improvement with metalayers that have almost the same dimensions as the patch. However, the proposed antenna system is more effective than Ku-band antennas in the literature due to its high directivity compared to similar ones. [ABSTRACT FROM AUTHOR]

In this study, the use of Split Ring Resonator SRR metamaterial (MM) lens for Ku band micro-strip patch antenna directivity gain improvement is shown. In order to obtain the focus in the Ku band, a SRR metamaterial lens with a negative refractive index in the same band is designed and placed in the half-wavelength distance of the reference antenna in the radial direction, and the simulation and measurement results are obtained separately. Thus, a 1.52 dBi increase in the directivity gain of the reference antenna is shown according to measurement results. In this study, the same dielectric materials are used for the substrate and superstrate, so that the beneficial effect of the lens layer on the directivity gain improvement is shown more clearly. Moreover, for the low antenna profile, the total size of the MM lens layer is almost the same as the patch size of the reference antenna. Another advantage of this study over other similar studies in the literature is the use of a lens layer consisting of a smaller number of metamaterial unit cells. [ABSTRACT FROM AUTHOR]

This paper proposes improving the directivity of microstrip patch antennas (MPAs) by using metamaterials. Four different metamaterial types are used as a at lens in front of the MPA, respectively, which are tuned to 12 GHz (Ku-band) resonance frequency. Thus, it can be decided which metamaterial is more proper for antenna directivity enhancement at this band. One additional new metamaterial structure is proposed in this paper, which is called a Euro-shaped resonator, and other metamaterials used are the triangular split ring resonator, symmetrical ring structure, and split ring resonator. The permeability and permittivity of metamaterials are extracted from the S parameters by using a robust method. Microwave Studio by Computer Simulation Technology is used for modeling and simulation. The MPA and metamaterials are fabricated, and measurements are performed in the Yíldíz Technical University RF and Microwave Laboratory. It is observed that measured results are in close agreement with the computer simulations. [ABSTRACT FROM AUTHOR]