![]() By reorienting the liquid crystal layer between the split square resonator (SSR), the bandwidth and unique properties of MM, such as the refractive index, can be controlled. In, the reconfigurable MM had been implemented by including a liquid crystal layer. The tunable and controllable transition from hyperbolic to elliptic dispersion was implemented using electrostatic biasing. This implementation shows promising features such as tuning of the MM. The MM that containing a multilayer of graphene material had been implemented at far- and mid-infrared spectrums. The graphene dramatically alters the transmission spectrum of the MM structure, thereby controlling the loss of such materials. The proposed MM exhibits exceptional sensitivity to the presence of the graphene layer. In, the authors propose an MM with a single layer of graphene placed on its surface. ![]() This method provides low-cost tunability and low loss in comparison with other methods. On the other hand, various additional materials had been proposed to reconfigure the MM structures, such as graphene and liquid crystal. Moreover, the drop in the gain is a common issue in most of the conventional beam deflection methods. However, these approaches suffer from bulky, high cost, and complex transceiver system. The phased array antenna and butler matrix networks are also used to guide the radiation pattern in the required direction. However, it suffers from inherent high loss due to the active components used. On the other hand, the electronic method provides high switching speed and small physical structure. Despite the drawbacks of bulky structure and low switching speed of the mechanical method, it provides a large scan angle in comparison with other methods. In the literature, the mechanical and electronic approaches have been proposed as conventional methods to perform beam tilting at the base station and mobile station. Deflecting an antenna’s radiation pattern in a predefined direction is very important for enhancing the performance of communication systems in terms of the quality of service, system security, avoiding interference, and economizing power. To overcome this problem, the high-gain directional antenna should be incorporated into both communication system terminals to overcome the greater path loss and enhance link quality. Although these bands provide multigigabits-per-second data rates and high bandwidth, they experience very high path loss based on Friis’s formula, which limits the range of communications to short-range distances when compared to sub-6 GHz frequencies. The well-known spectrum candidate for delivering 5G is millimeter-wave (MMW), which includes bands such as 28 and 60 GHz. 5G networks provide data rates of up to 1000 times higher and bandwidth 10 times greater than current communication networks. Therefore, service providers have moved toward fifth-generation (5G) networks to meet these requirements. The rapid increase in the number of wireless service users has created serious challenges for telecommunications industries regarding bandwidth scarcity in current networks. The MM antennas are manufactured and measured to validate the simulated results. The reflection coefficients of the MM antenna are kept below −10 dB for both deflection angles at 28 GHz. Furthermore, these deflections are accompanied by gain enhancements of 1.9 dB (26.7%) and 1.5 dB (22.4%) for the positive and negative deflections, respectively. The simulation results of the proposed antenna loaded by MM unit cells demonstrate that the radiation beam is deflected by angles of +30° and −27° in the E-plane, depending on the arrangement of the two MM configurations on the antenna substrate. The CSR is reconfigured using three switches to achieve two MM configurations with different refractive indices. A contiguous squares resonator (CSR) is proposed as an MM structure to operate at MMW band. The different refractive indices of the two MM configurations created phase change for the electromagnetic (EM) wave of the antenna, which deflected the main beam. These two MM configurations are used to guide the antenna’s main beam in the desired direction in the 5th generation (5G) band of 28 GHz. In this research, a reconfigurable metamaterial (MM) structure was designed using a millimeter-wave (MMW) band with two configurations that exhibit different refractive indices.
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