Theses and Dissertations
Permanent URI for this community
Browse
Browsing Theses and Dissertations by Author "Aloi, Daniel N"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item CELLULAR 5G AND V2X ANTENNAS DESIGN FOR AUTOMOTIVE APPLICATIONS(2022-03-14) Khalifa, Mohamed Osman Hussein; Aloi, Daniel N; Kaur, Amanpreet; Cheng, Eddie; Azadegan, RezaThe work presented in this dissertation involves investigation and development of antennas and antenna systems that can contribute to autonomous vehicles realization. The antennas targeted in this work are namely Fifth Generation (5G) cellular antennas and Vehicle to Everything (V2X) antenna. The studies conceived in this work followed a scientific approach which starts by accurately simulating the antennas using three dimensional Electromagnetics (EM) solver High Frequency Simulator System (HFSS) software on one meter rolled edges GND. Then antenna and antenna systems were measured on one-meter GND inside anechoic chamber and also measured either on the top of vehicle roof or at the vehicle’s windshield. Phase one of this work starts by presenting a multi-wideband branched monopole antenna that covers 5G cellular bands between 617MHz- 5000MHz. This antenna utilizes two arms and L-Shape slot structure to provide coverage for low, mid, and high 5G cellular bands and also to reject Global Navigation Satellite System (GNSS) frequency bands. The antenna has compact size, light weight, low cost, and excellent gain characteristics at the solid angle facing cellular base station communication towers. The design, simulated, and measured results were presented and discussed in detail. Phase two of this work uses the element developed in phase one to construct high order Multiple-Input-Multiple-Output (MIMO) structure in order to boost overall system throughput, capacity, and data rate. Three MIMO systems configurations were studied, the first two are 2x2 5G cellular MIMO systems with similar individual antenna elements and opposite antennas orientations whereas the third configuration is a 4x4 5G cellular MIMO system. The individual antennas performance, diversity radiation pattern, and correlation between antennas were reported and discussed for all three MIMO configurations. Phase three of this work presents a V2X cavity-backed slot antenna that can be mounted in the vehicle’s windshield or rear-view mirror. The antenna is GND independent, and it provides excellent below horizon performance allowing the vehicles to communicate with other objects of less height. The antenna can be used as a building block to implement a full V2X system that provides null-free omnidirectional coverage at V2X solid angle of interest while providing aesthetic look for the vehicle which makes it very attractive in the automotive industry. The antenna was simulated and measured, and its radiation pattern, gain, and efficiency were presented and discussed in detail.Item Innovative Designs For Low Profile Antenna Systems For Mimo 5G/V2X And Gnss Communications(2022-11-07) Yacoub, Ahmad; Aloi, Daniel N; Cesmelioglu, Aycil; Li, Jia; Qu, GuangzhiThe research in this dissertation shows the analysis and development of designing antenna elements and MIMO antenna systems that can be implemented in the automotive industry and have a significant role in an autonomous driving system. The antennas presented in this research cover 5G-sub-6GHz bands which have much more extended bandwidth compared to previous LTE network, in addition to covering Vehicle-to-Everything (V2X) frequency band. The design work presented in this research followed a scientific method that included simulating the antenna element using 3-D electromagnetic solver (HFSS) on 1-meter ground plane. The antenna was then fabricated using properlycut metal sheet, measured on 1-meter rolled-edge ground plane, and measured on a vehicle’s roof inside an anechoic chamber for practical measurements. The design guidelines and measurements are discussed in detail throughout this work. The first two sections of this research begin with presenting a novel wideband low-profile Planar Inverted F-Antenna (PIFA) that covers a wide frequency range (617MHz-6000MHz) that includes cellular 5G bands and V2X band while having reasonable rejection for Global Navigation Satellite System (GNSS) frequency bands. Then, Multiple MIMO configurations based on the novel PIFA design are studied by using spatial diversity, rotational diversity, and orthogonal diversity to increase the total throughput and data rate of the system. The performance of each element in the MIMO system is analyzed and discussed to evaluate the functionality of the system. The third section of this work introduces a 2x2 MIMO antenna system for vehicular application in the sub-6GHz 5G systems that operates in the middle and high frequency bands from 1.71GHz to 5GHz. The design consists of two novel raised printed monopoles on Flame Retardant 4 (FR4) dielectric material with Partial Ground Plane (PGP) structure to improve bandwidth impedance and achieve higher isolation across the operating frequency range. The design is an excellent candidate to be implemented in a shark-fin housing due to its low-profile characteristics and good electrical performance. Eventually, in the fourth section of this work, a fully integrated low-profile antenna systems for MIMO 5G and global navigation satellite system (GNSS) for L1/L5 frequency bands is presented. The designs can be used on the vehicle’s roof inside a low profile housing due to its physical parameters and RF performance.