Design of a New Compact Printed MonopoleAntenna by using Tuning Stub for UWB Applications

Wideband applications put a new demand on antennas pertaining to size, gain, efficiency, bandwidth and more. This paper presents the design and analysis of a new compact broadband coplanar slot antenna for multiple wireless communication applications. The antenna structure is based on the CPW-fed combined with slot technique, stub tuning and a modified geometry antenna in order to enlarge the bandwidth. The antenna parameters have been investigated and optimized by using CST Microwave Studio with a comparison of the results by using another simulator ADS” Advanced Design System from Agilent Technologies. The simulated input impedance bandwidth, ranging from 8GHz to 23GHz, is obtained with a return loss less than -10dB, corresponding to 96.77% at 15.5GHz as a center frequency. Details of the proposed antenna design and simulated results are described and discussed

Contribución al desarrollo de herramientas CAD para el análisis y diseño de antenas de banda ultra ancha mediante el método de elementos finitos : Contribution to the development of CAD tools for the analysis and design of ultra-wideband antennas by means of the finite element method

RESUMEN ------- Esta tesis doctoral está dedicada al desarrollo de herramientas de diseño asistido por ordenador (CAD) y de optimización de antenas de banda ultra ancha (UWB) mediante el método de elementos finitos (FEM). El objetivo de este trabajo es adecuar una técnica de análisis numérico versátil, fiable y precisa como es el FEM, pero a su vez sumamente costosa en términos de recursos de computación, para su uso en conjunción con algoritmos de optimización y la creación de herramientas CAD. Así, gracias a la versatilidad proporcionada por el método de análisis, se pueden abordar optimizaciones ciegas sobre formas arbitrarias, de forma que se puedan explorar y estudiar nuevas geometrías con mejores prestaciones que ayuden a evolucionar el estado del arte en antenas UWB. Es, por tanto, también objetivo de este trabajo el diseño y optimización de geometrías de antena UWB novedosas cuyas prestaciones las sitúen a la cabeza del estado del arte. Teniendo en cuenta estos objetivos, este trabajo se ha dividido en dos partes principales: una dedicada a los fundamentos teóricos que permiten aumentar la eficiencia del FEM de manera que pueda ser integrado en rutinas de optimización, y una segunda dedicada al diseño de antenas de banda ultra ancha con las herramientas desarrolladas. Acompañando estos dos bloques temáticos principales se encuentran también una introducción, cuyo objetivo es presentar los antecedentes y motivaciones del trabajo, y unas conclusiones, cuyo objetivo es resaltar las contribuciones originales de este trabajo y las líneas de trabajo futuras abiertas por este trabajo. Dentro del primer bloque temático, se presentan dos metodologías diferentes cuyo objetivo es dotar de una mayor efiencia al método del elementos finitos: la formulación SFELP y el análisis mediante matrices de admitancia multipropósito (MAM). La primera se basa en el desarrollo de una formulación que permite la obtención de la matriz de admitancia generalizada (GAM) de una estructura electromagnética de una forma eficiente, de manera que puede realizarse la segmentación del dominio mediante la conexión de las GAM de los diferentes segmentos. El análisis mediante MAM se basa, en cambio, en la resolución de problemas electromagnéticos utilizando puertas artificiales, mediante las cuales se pueden establecer condiciones de contorno variables que pueden fijarse a posteriori una vez realizado el análisis electromagnético, mediante simples y eficientes manipulaciones circuitales. De esta manera puede abordarse la optimización de estructuras muy complejas de una forma muy eficiente. El segundo bloque temático se adentra en el diseño y estudio de geometrías de antena UWB con perfiles optimizados para mejorar sus prestaciones. Este bloque se divide en cuatro capítulos en los que se presenta el diseño y optimización de otros tantos tipos de estructura de banda ultra ancha. En el primero de esos capítulos se aborda el estudio y optimización del perfil de antenas de tipo monopolo (tanto estructuras con perfil plano como estructuras tridimensionales) con el objetivo de minimizar las pérdidas de retorno. Como evolución de dichas estructuras, el siguiente capítulo presenta el diseño y optimización de monopolos con perfil plano y banda rechazada mediante la optimización de ranuras en el perfil. En el tercer capítulo se trata el diseño de una antena de apertura con polarización dual con perfil de alimentación optimizado para minimizar las pérdidas de retorno en la banda UWB. Por último, el cuarto diseño aborda la posibilidad del conformado del haz de radiación mediante la optimización del perfil de un dieléctrico utilizado a modo de recubrimiento en una antena de tipo monopolo. ABSTRACT -------- This thesis is devoted to the development of computer aided design (CAD) tools for the optimization of Ultra Wide-Band antennas by means of the Finite Element Method (FEM). The objective of this work is to adequate the versatile and accurate but costly in terms of computational resources, the FEM is, for its use together with optimization algorithms and other CAD tools. Hence, thanks to the versatility provided by the analysis method, blind optimizations can be carried out over arbitrary profiles, so that new geometries can be explored and studied in order to make the state of the art in UWB antennas evolve. Therefore, the design and optimization of novel UWB antennas with performances which make them situate in the head of the state of the art, is another objective of this work. Keeping in mind these objectives, this work has been divided into two main parts: one dedicated to the theoretical basis which allow to increase the efficiency of the FEM so that it can be used together with optimization routines, and a second one dedicated to the design of ultra-wideband antennas with the developed tools. Together with these two main thematic blocks there is also an introduction, whose objective is to present the background and motivations of this work, and a conclusion chapter, whose objective is to highlight the original contributions of this thesis and the future research work related to this thesis. In the first part, two different methodologies are presented, in order to provide the finite element method with a higher efficiency: the SFELP formulation and the MAM-based analysis. The first one is based on the development of a formulation which allows to obtain the GAM of an electromagnetic structure in an efficient way, so that a segmentation of the domain can be performed by means of the connection of the GAM of the different segments. The MAM analysis is based in the use of artificial ports when computing an electromagnetic problem, which allow to establish variable boundary conditions which can be fixed a posteriori once the electromagnetic analysis has been completed, by means of simple and efficient circuital manipulations. Hence, the optimization of very complex structures can be carried out in a very efficient way. The second part presents the design and study of UWB structures with optimized profiles for better performances. This part is divided into four chapters in which the design and optimization of four types of ultra-wideband antennas is performed. The first chapter is devoted to the study and optimization of monopole-like (both planar and non-planar profiles) antennas designed to minimize return losses. As an evolution of these structures, the second chapter presents the design and optimization of frequency notched planar profile monopole antennas in which the notches of the antenna are optimized for optimal performance. The third chapter treats the design of a dual polarized aperture antenna an optimized profile feed for minimum return losses in the UWB band. Finally, the fourth design deals with the possibility of radiation pattern conforming by means of an optimized profile dielectric coating in a monopole antenna

Design and analysis of wideband passive microwave devices using planar structures

A selected volume of work consisting of 84 published journal papers is presented to demonstrate the contributions made by the author in the last seven years of his work at the University of Queensland in the area of Microwave Engineering. The over-arching theme in the author’s works included in this volume is the engineering of novel passive microwave devices that are key components in the building of any microwave system. The author’s contribution covers innovative designs, design methods and analyses for the following key devices and associated systems: Wideband antennas and associated systems Band-notched and multiband antennas Directional couplers and associated systems Power dividers and associated systems Microwave filters Phase shifters Much of the motivation for the work arose from the desire to contribute to the engineering o

Mutual coupling suppression in multiple microstrip antennas for wireless applications

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonMutual Coupling (MC) is the exchange of energy between multiple antennas when placed on the same PCB, it being one of the critical parameters and a significant issue to be considered when designing MIMO antennas. It appears significantly where multiple antennas are placed very close to each other, with a high coupling affecting the performance of the array, in terms radiation patterns, the reflection coefficient, and influencing the input impedance. Moreover; it degrades the designed efficiency and gain since part of the power that could have been radiated becomes absorbed by other adjacent antennas’ elements. The coupling mechanism between multiple antenna elements is identified as being mainly through three different paths or channels: surface wave propagation, space (direct) radiation and reactive near-field coupling. In this thesis, various coupling reduction approaches that are commonly employed in the literature are categorised based on these mechanisms. Furthermore, a new comparative study involving four different array types (PIFA, patch, monopole, and slot), is explained in detail. This thesis primarily focuses on three interconnected research topics for mutual coupling reduction based on new isolation approaches for different wireless applications (i.e. Narrowband, Ultra-wide-band and Multi-band). First, a new Fractal based Electromagnetic Band Gap (FEBG) decoupling structure between PIFAs is proposed and investigated for a narrowband application. Excellent isolation of more than 27 dB (Z-X plane) and 40 dB (Z-Y plane) is obtained without much degradation of the radiation characteristics. It is found that the fractal structures can provide a band-stop effect, because of their self-similarity features for a particular frequency band. Second, new UWB-MIMO antennas are presented with high isolation characteristics. Wideband isolation (≥ 31 dB) is achieved through the entire UWB band (3.1-10.6 GHz) by etching a novel compact planar decoupling structure inserted between these multiple UWB antennas. Finally, new planar MIMO antennas are presented for multi-band (quad bands) applications. A significant isolation improvement over the reference (≥ 17 dB) is achieved in each band by etching a hybrid solution. All the designs reported in this thesis have been fabricated and measured, with the simulated and measured results agreeing well in most cases

Antenna Designs for 5G/IoT and Space Applications

This book is intended to shed some light on recent advances in antenna design for these new emerging applications and identify further research areas in this exciting field of communications technologies. Considering the specificity of the operational environment, e.g., huge distance, moving support (satellite), huge temperature drift, small dimension with respect to the distance, etc, antennas, are the fundamental device allowing to maintain a constant interoperability between ground station and satellite, or different satellites. High gain, stable (in temperature, and time) performances, long lifecycle are some of the requirements that necessitates special attention with respect to standard designs. The chapters of this book discuss various aspects of the above-mentioned list presenting the view of the authors. Some of the contributors are working strictly in the field (space), so they have a very targeted view on the subjects, while others with a more academic background, proposes futuristic solutions. We hope that interested reader, will find a fertile source of information, that combined with their interest/background will allow efficiently exploiting the combination of these two perspectives

Microstrip antenna design with improved fabrication tolerance for remote vital signs monitoring and WLAN/WPAN applications at mm-wave and THz frequencies

A novel approach is introduced to design microstrip patch antennas (MPAs) with improved fabrication tolerance for highly demanded Millimetre-wave (mm-wave) (30-300GHz) and Terahertz (THz) (0.3-3THz) frequency applications. The presented MP A designing method overcomes the challenges which exist with the fabrication and implementation of the conventional MP A designs at mm-wave and THz frequencies. The following research contributions have been added to the state-ofthe- art work: (i) designing of improved size MPAs at 60GHz, 1 OOGHz, 635GHz and 835GHz to prove the designing concept, (ii) detail measurements and analysis of Remote Vital Signs Monitoring (RVSM) with various sizes of the proposed MPA arrays at 60GHz for high detection accuracy and sensitivity, (iii) designing and tes~ing of MP As for 60GHz wireless local and personal area networks (WLAN/WP AN) in point-to-pint, point-to-multipoint and dual-band applications, (iv) implementation and testing of particular Partially Reflective Surface, Dielectric Lens and Defected Ground Structures on the proposed MP A designs with novel configurations at 60GHz for bandwidth and gain enhancement, and (v~ a comprehensive experimental study on the performance of large array designs with the proposed MP A elements for mm-wave applications. The mentioned research work is explained in the coming chapters in details. Moreover, all mentioned work has already been published

Programmable Microwave Devices (PMDs) based on Liquid Metal

This thesis presents microwaves device which we term a programmable microwave device (PMD). This thesis presents building block elements (BBEs)/PMDs which can realize functional and parametric reconfiguration. This thesis also discusses how to implement Gallium-based liquid metal in a reconfigurable circuit/antenna. Two works were finished and presented in this thesis. The first work presented a BBE and a PMD that can realize the functional reconfiguration. The proposed BBE/PMD can alter its function between non radiating (resonator/filter) mode and radiating (antenna) mode. The proposed BBE/ PMD realizes functional reconfiguration with the aid of liquid metal (LM). The proposed single BBE operates in resonator mode when the fluidic channels are filled with liquid metal. Whereas it operates in antenna mode when the fluidic channels are emptied of liquid metal. When several BBEs are cascaded, they form a PMD. A PMD can realize filter mode operation when the fluidic channels are filled with liquid metal or antenna mode operation when liquid metal is withdrawn. In this work, an easy approach of 2D-shaping LM was also introduced. This approach allows 2D-shaped LM for being used in realizing reconfiguration. When operating in the antenna mode the proposed PMDs provides a measured peak realized gain of 7.23 dBi and a simulated total efficiency of 84%. When operating in the filter mode the proposed PMDs provides a band pass response and exhibits a maximum insertion loss of 1.9 dB, within the passband. The filters have a 10 dB return loss bandwidth of 340 MHz ranges from 2.28 GHz to 2.62 GHz. The second work presents an operating frequency reconfigurable antenna mode BBE, which realizes a wide operating frequency reconfiguring range with the aid of liquid metal. The capability of LM could have a significant impact on reconfigure capability of the proposed PMD. We firstly designed and manufactured a hardwired version of operating frequency reconfigurable antenna mode BBE. After we verified the measurement results of hardwired antenna mode BBE, we 3D-printed the fluidic channels using Polylactic acid (PLA). LM can be filled into the 3D-printed fluidic channels with a changeable length which tunes the operating frequency of the antenna mode BBE. The measurement results of the operating frequency reconfigurable antenna mode BBE agree with the simulation results, verifying the capability of this antenna mode BBE

Antenna System Design for 5G and Beyond – A Modal Approach

Antennas are one of the key components that empower a new generation of wireless technologies, such as 5G and new radar systems. It has been shown that antenna design strategies based on modal theories represent a powerful systematic approach to design practical antenna systems with high performance. In this thesis, several innovative multi-antenna systems are proposed for wireless applications in different frequency bands: from sub-6 GHz to millimeter-wave (mm-wave) bands. The thesis consists of an overview (Part I) and six scientific papers published in peer-reviewed international journals (Part II). Part I provides the overall framework of the thesis work: It presents the background and motivation for the problems at hand, the fundamental modal theories utilized to address these problems, as well as subject-specific research challenges. Brief conclusions and future outlook are also provided. The included papers of Part II can be divided into two tracks with different 5G and beyond wireless applications, both aiming for higher data rates.In the first track, Papers [I] to [IV] investigate different aspects of antenna system design for smart-phone application. Since Long Term Evolution (LTE) (so-called 3.5G) was deployed in 2009, mobile communication systems have utilized multiple-input multiple-output antenna technology (MIMO) technology to increase the spectral efficiency of the transmission channel and provide higher data rates in existing and new sub-6 GHz bands. However, MIMO requires multi-antennas at both the base stations and the user equipment (mainly smartphones) and it is very challenging to implement sub-6 GHz multi-antennas within the limited space of smartphones. This points to the need for innovative design strategies. The theory of characteristic modes (TCM) is one type of modal theory in the antenna community, which has been shown to be a versatile tool to analyze the inherent resonance properties of an arbitrarily shaped radiating structure. Characteristic modes (CMs) have the useful property of their fields being orthogonal over both the source region and the sphere at infinity. This property makes TCM uniquely suited for electrically compact MIMO antenna design.In the second track, Papers [V]-[VI] investigate new integrated antenna arrays and subarrays for the two wireless applications, which are both implemented in a higher part of the mm-wave frequency range (i.e. E-band). Furthermore, a newly developed high resolution multi-layer “Any-Layer” PCB technology is investigated to realize antenna-in-package solutions for these mmwave antenna system designs. High gain and high efficiency antennas are essential for high-speed wireless point-to-point communication systems. To meet these requirements, Paper [V] proposes directive multilayer substrate integrated waveguide (SIW) cavity-backed slot antenna array and subarray. As a background, the microwave community has already shown the benefits of modal theory in the design and analysis of closed structures like waveguides and cavities. Higher-order cavity modes are used in the antenna array design process to facilitate lower loss, simpler feeding network, and lower sensitivity to fabrication errors, which are favorable for E-band communication systems. However, waveguide/cavity modes are confined to fields within the guided media and can only help to design special types of antennas that contain those structures. As an example of the versatility of TCM, Paper [VI] shows that apart from smartphone antenna designs proposed in Papers [I]-[IV], TCM can alsobe used to find the desirable modes of the linear antenna arrays. Furthermore, apart from E-band communications, the proposed series-fed patch array topology in Paper [VI] is a good candidate for application in 79 GHz MIMO automotive radar due to its low cost, compact size, ability to suppress surface waves, as well as relatively wide impedance and flat-gain bandwidths

Impedance Transformers

Non

Intelligent Circuits and Systems

ICICS-2020 is the third conference initiated by the School of Electronics and Electrical Engineering at Lovely Professional University that explored recent innovations of researchers working for the development of smart and green technologies in the fields of Energy, Electronics, Communications, Computers, and Control. ICICS provides innovators to identify new opportunities for the social and economic benefits of society.　 This conference bridges the gap between academics and R&D institutions, social visionaries, and experts from all strata of society to present their ongoing research activities and foster research relations between them. It provides opportunities for the exchange of new ideas, applications, and experiences in the field of smart technologies and finding global partners for future collaboration. The ICICS-2020 was conducted in two broad categories, Intelligent Circuits & Intelligent Systems and Emerging Technologies in Electrical Engineering