DESIGN AND ANALYSIS OF ANTENNA FOR 5G WIRELESS COMMUNICATIONN

Abstract

The fifth generation (5G) technology for cellular communication utilizes three main frequency bands: low band (600-850 MHz), mid band (3.4-3.6 GHz), and high band (24- 30 GHz). Each of these bands has some distinct advantages and disadvantages. For fast data communication, 5G networks utilize the mid band frequencies, which also necessitate smaller antenna components. In this thesis we explore Single-Input Single-Output (SISO) and Multi-Input Multi-Output (MIMO) microstrip patch antennas that meet the gain, band-width, efficiency and diversity parameters for 5G wireless technology. Further, simulation, analysis, and testing are conducted to achieve a highly efficient, low-profile MIMO antenna specifically designed for 5G applications. A microstrip patch antenna for 5G communication with highly reflecting metasurface (MS), excited by a coplanar waveguide (CPW) feed is designed. This antenna is suitable for the frequency band 3.86 GHz to 4.49 GHz. The use of MS enables to achieve a higher gain, wider bandwidth, smaller return losses, and better efficiency. Also, a Fabry Perot cavity-based microstrip patch antenna for 5G communication is investigated to achieve higher gain. The Fabry Perot cavity based antenna used three techniques: a perfect electric conductor (PEC) sheet, high dielectric superstrate, and metasurface superstrate. The size of the PEC sheet needs to be kept large to reflect the radiation resulting in larger antenna size. A high dielectric superstrate provides better return loss and gain as compared to PEC, however it increases the antenna cost. Finally, metasurface superstrate is explored in the design microstrip patch antenna for 5G communication which has better gain, bandwidth and return loss as compared to PEC and dielectric superstrate antennas. Further, simulation, analysis are also performed to design highly efficient, low-profile MIMO antenna tailored for 5G applications. A closely integrated MIMO patch antennas operating at 3.5 GHz with improved isolation is designed. This configuration comprises of two mirror-symmetrical single-feed patch antennas with a separation of 0.011 λ0 is implemented. A metasurface is employed as a decoupling structure that consists of pairs ii of uniform cut wires. An enhanced isolation of 10dB to 35dB between the closely spaced antennas is achieved by employing the metasurface and gain of 3.85 dBi. Further to reduce antenna size, a two-port circularly polarized (CP) MIMO antenna operating at sub-6 GHz with a distinctive slot and a circular split ring resonator (SRR) at the ground plane is designed. A sequence of parasitic elements in the shape of ‘h’ is placed in the space between the two antenna elements for decoupling. The designed antenna has an impedance bandwidth of 3.3 to 3.6 GHz, axial ratio bandwidth of 3.35 to 3.51 GHz and minimum 20 dB isolation. An innovative integrated dual-band MIMO antenna featuring unit cells arranged orthogonally and fed by a CPW is designed. By incorporating a curved design into the antenna's radiator elements, the antenna effectively operates in two resonant frequencies: 3.5 GHz (Wi-Max) and 5.5 GHz (WLAN). This design eliminates the need for additional isolation components while still achieving high isolation. Finally, a triple-band two-port MIMO antenna with self-isolation was designed for the frequency bands: 2.58 GHz to 2.84 GHz, 3.4 GHz to 3.9 GHz, and 4.3 GHz to 4.6 GHz. The gain enhancement, radiation pattern, radiation efficiency, MIMO diversity parameters using microstrip patch antenna and other key aspects are presented in the thesis.