Electrical and Computer Engineering

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https://hdl.handle.net/10323/11889

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Browsing Electrical and Computer Engineering by Author "Aloi, Daniel N"

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    Cellular 5G And V2X Antennas Design for Automotive Applications
    (2022-03-14) Khalifa, Mohamed Osman Hussein; Aloi, Daniel N; Kaur, Amanpreet; Cheng, Eddie; Azadegan, Reza
    The 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.
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    Design of a Compact Multi-Band (Cellular 5g/GNSS/V2x) Antenna and Rigorous Analysis of Antenna Performance on Glass Roofs for Vehicular Platforms
    (2023-01-01) Ibrahim, Ahmad Abu Elhassan Salih; Aloi, Daniel N; Kaur, Amanpreet; Qu, Guangzhi; Shaska, Tony
    The growing market competition between the automakers led to the implementation of more entertainment systems and extra features to satisfy the automotive customers. The entertainment systems depend on wireless services and communication which led to increasing numbers of antennas mounted on and inside the vehicles. This dissertation is focused on automotive antenna design and the effect of the vehicle environment on the antenna performance. For the first part of the dissertation, a compact multi-band monopole antenna is designed for vehicular roof top shark-fin applications. The proposed multi-band antenna covers 5G sub-6GHz, GNSS and V2X frequency bands starting at 617MHz to 5925MHz. The presented antenna is a three-dimensional monopole antenna with two branches to cover the required bands with compact size to fit inside a roof top shark-fin. The antenna is simulated, optimized and then a prototype is fabricated, and its radiation characteristics are measured when mounted on one-meter ground plane and on a vehicle's roof. For the second part of the dissertation, the analysis of a C-V2X quarter-wavelength monopole antenna performance when mounted on a vehicle's glass roof is presented. Antenna gain measurements performed on a full glass roof exhibited a performance degradation in a linear average gain of 8 dB compared to when the same antenna is mounted on a metallic ground plane. In addition, the antenna radiation pattern on the glass roof had deep nulls. The antenna was simulated using a full-wave, three-dimensional electromagnetic field solver on the full glass sample with low emissivity (low-E) coating on the edges of the full glass roof and the simulation results showed acceptable agreement with the measurements. Simulation shows that the C-V2X antenna performance on the full glass roof can be improved by moving the low-E coating from underneath the glass to top of the glass
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    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, Guangzhi
    The 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.
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    Modeling and Control of Heat Transfer in a Single Vertical Ground Heat Exchanger for a Geothermal Heat Pump System
    (2023-01-01) Salhein, Khaled Asharef Assudani; Zohdy, Mohamed A; Kobus, Christopher J; Aloi, Daniel N; Olawoyin, Richard; Schmidt, Darrell P
    The Ground Heat Exchanger (GHE) is regarded as the most critical component of a Geothermal Heat Pump System (GHPS) due to its direct contact with the Earth and ability to benefit from its relatively steady temperature. A GHE can attain the maximum benefit from the Earths heat when the water temperature reaches the ground, which occurs when the water velocity is moderate, allowing the heat exchanger to balance. Optimally, controlling water velocity is crucial such that the water reaches the desired temperature. Therefore, in this dissertation, I proposed a novel mathematical model of heat transfer behavior between the water inside the underground pipe and the surrounding ground for heating and cooling modes in a GHE. The proposed dynamic model was applied to three case studies of GHPS at Oakland University, the University Politècnica de València, and Oklahoma State University in heating and cooling modes to assess its validity and further enhance the performance of the GHE by determining the optimum velocity range. The results revealed the optimal water velocity ranges for three GHPSs. Model Predictive Control (MPC) was designed to optimize the GHE’s output temperature by controlling the water velocity, which can reduce the power consumption used for the water circulation pump and therefore maximize efficiency. In this dissertation, I also introduced an Improved Grey Prediction Model (IGM (1,1)). The proposed IGM (1,1) model was based on optimizing the current predicted value by subtracting the error prediction between the previous accumulated time response of the GM (1,1) model and the previous background value throughout the prediction length. The IGM (1,1) model was applied to perform the GHPS’s output temperature prediction eight hours in advance at Oklahoma State University, the University Politècnica de València, and Oakland University, respectively. Thus, the IGM (1,1) model outperformed the traditional GM (1,1) model for all used datasets.
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    NOVEL AUTOMOTIVE ANTENNA DESIGNS UTILIZING CHARACTERISTIC MODE ANALYSIS
    (2023-01-01) Abdul-Rahman, Ehab Mahmoud; Aloi, Daniel N; Li, Jia; Nassar, Sayed; Schmidt, Darrell
    The Theory of Characteristic Modes (TCM) provides a valuable method for antenna analysis. It helps decompose the total radiation into a set of orthogonal radiation modes. Each mode exhibits a unique reaction in terms of its current distribution and radiation pattern. TCM has proven helpful in numerous antenna design applications, such as enhancing radiation patterns, decoupling antennas, increasing bandwidth, and achieving input impedance match.This study aims to apply characteristic mode analysis (CMA) to address automotive antenna design challenges. The work involves synthesizing and controlling the desired radiation characteristic mode (CM) at the intended frequency range to achieve an excellent radiation pattern for automotive applications. The study focuses on practical antenna design for the newly defined 5G-sub 6GHz cellular bands in the 0.617-5 GHz range and its cooperation with other coexisting wireless antennas for other wireless functions.