Optimization of millimeter-wave by using Metasurfaces for upcoming 5G and 6G wireless communication system

The evolutions in the field of wireless communication have a significant impact not only on the environment but also on our daily life. The researchers are working to find the best way to exploit the mmWave band that means above 30 GHz frequency, to ensure faster communication in a cheaper way with a higher bit rate and less lossy system. This thesis work mainly focuses on the path of implementation of a new method for wireless communication with a higher frequency and controlled environment for the upcoming time. The marvelous artificial material, i.e., Metasurface, is used here to optimize the antennas/devices in the mmWave band for future generations of wireless technology. Metasurfaces have an ability to regulate EM waves in suitable directions to ensure that communication is happening in a reliable manner; in other words, a completely controlled environment of electromagnetic waves. The tunability effect of metasurfaces can achieve these exceptional outcomes that are controllability and directionality of electromagnetic waves. To observe the performance of the metasurfaces in the mmWave band, and to find the best results using these materials, Microwave Studio by CST is used for simulation purposes. The characterization for the different considered structures is carried out in terms of a dispersion diagram. The dispersion diagram shows the frequency behavior of materials; it tells how much phase shift the materials have at a specific frequency when a propagating wave propagates from the input to the output port of the single unit cell. In this work, various kinds of metasurfaces geometrical shapes are used to acquire the behavior of these structures in the mmWave band frequency. For this reason, here 70 GHz is used to obtain the proper findings by following the title of this research work. The dielectric that is used in the simulation part is Polyimide. It has one of the best thermal expansion coefficients that means a rate at which the length of material is growing with an increment of temperature. The polyimide is suitable for being known as a thermally stable dielectric; they are preferably higher in a choice as a dielectric at high temperature. To check the tunability of metasurface from a physical implementation point of view, here we utilize this dielectric; thus, by changing polyimide thickness/height in the simulator, the observation will be made for the physical execution of self-made materials in terms of tunability or regulation of EM waves. This research is quite helpful for all who have an interest in metasurfaces and also willing to perceive the performance of these artificial materials at the mmWave band. Here one can find the essential guidance of materials, wireless generations, divergent outcomes, responses of material shapes with multiple thickness/height of substrate material, and the future aspects of these kinds of explorations also. The future belongs to high data rate, reliability, security, ultra-low latency, and controlled EM waves or a smart radio environment. On account of this, some beneficial information is described here; manifestly, the prime goal of this thesis is to find a way to earn these things in a cheaper way. Consequently, the metasurfaces have many more applications, but in this thesis, the focus is only on the high-frequency response of these remarkable artificial materials.