A Compact and Low Profile Loop Antenna with Six Resonant Modes for LTE Smart phone

In this paper, a novel six-mode loop antenna covering 660-1100 MHz, 1710-3020 MHz, 3370-3900 MHz, and 5150-5850 MHz has been proposed for the application of Long Term Evolution (LTE) including the coming LTE in unlicensed spectrum (LTE-U) and LTE-Licensed Assisted Access (LTE-LAA). Loop antennas offer better user experience than conventional Planar Inverted-F Antennas (PIFA), Inverted-F Antennas (IFA), and monopole antennas because of their unique balanced modes (1?, 2?, …). However, the bandwidth of loop antennas is usually narrower than that of PIFA/IFA and monopole antennas due to these balanced modes. To overcome this problem, a novel monopole/dipole parasitic element, which operates at an unbalanced monopole-like 0.25? mode and a balanced dipole-like 0.5? mode, is first proposed for loop antennas to cover more frequency bands. Benefiting from the balanced mode, the proposed parasitic element is promising to provide better user experience than conventional parasitic elements. To the authors’ knowledge, the balanced mode for a parasitic element is reported for the first time. The proposed antenna is able to provide excellent user experience while solving the problem of limited bandwidth in loop antennas. To validate the concept, one prototype antenna with the size of 75×10×5 mm3 is designed, fabricated and measured. Both simulations and experimental results are presented and discussed. Good performance is achieved

Radio Frequency Interference Impact Assessment on Global Navigation Satellite Systems

The Institute for the Protection and Security of the Citizen of the EC Joint Research Centre (IPSC-JRC) has been mandated to perform a study on the Radio Frequency (RF) threat against telecommunications and ICT control systems. This study is divided into two parts. The rst part concerns the assessment of high energy radio frequency (HERF) threats, where the focus is on the generation of electromagnetic pulses (EMP), the development of corresponding devices and the possible impact on ICT and power distribution systems. The second part of the study concerns radio frequency interference (RFI) with regard to global navigation satellite systems (GNSS). This document contributes to the second part and contains a detailed literature study disclosing the weaknesses of GNSS systems. Whereas the HERF analysis only concerns intentional interference issues, this study on GNSS also takes into account unintentional interference, enlarging the spectrum of plausible interference scenarios.JRC.DG.G.6-Security technology assessmen

Ground plane booster antenna technology for wireless handheld devices

This thesis is framed in the field of mobile communications and more particularly in handset antennas. The wireless industry is constantly growing, which entails challenging handset antenna specifications. Handset antennas not only have to be multi-band for satisfying the great number of communication services, but also sufficiently small as for fitting in the reduced space imposed by the handset platforms. The appearance of the MIMO (Multiple Input Multiple Output) technology, further exacerbates these challenges. In order to satisfy these requirements, this thesis proposes the use of the ground plane, inherently present in any handset platform, as the main radiator. Electrically small nonresonant elements, called along this thesis as ground plane boosters, are used to transfer energy to this ground plane. The solution removes the need of including a dedicated antenna featured by considerable dimensions, thus releasing space to integrate other antennas, as well as, other handset components, services and functionalities.Postprint (published version

Etude des Antennes à Résonateurs Diélectriques. : Application aux Réseaux de Télécommunications

A fast technological development in the telecommunications domain, as mobile telephony, wireless networks, TV over Satellite, Radar Applications (civil or military)…etc, is observed. This considerable growth has led to enormous needs and caused a major technological evolution in antennas. These have to face different needs such as gain improvement, bandwidth enlargement, and different existing problems, such as cost and overcrowding…etc. Though, our goal is to design antenna topologies that are simple, having Low overcrowding and relatively with high gain operating in multiband and/or ultra large. To achieve this we headed to Dielectric Resonator Antennas (DRA) in UHF and SHF bands. Recently they have been the subject of several studies and have gained great interest from both academic and industrial sectors. Due to their diverse and simple geometries, they can be fed with different usual techniques. Furthermore, they can be smaller than patch antennas. The first part of this work has focused on the study of cylindrical DRAs, and then a validation of the simulating tool has been done after comparison with measurement results. For a multi-standard utilization, enlargement antennas’ operating bands, to have bi-band behaviour, get a modification of the resonant frequency and also a reduction of the overcrowding, the second part is dedicated to the study of new resonator topologies based on a vertical and radial stack of two cylinders, and then a multilayer and ring topologies. The obtained results found their applications in GSM900-DCS1800-UMTS-WiFi…Un développement technologique rapide dans le domaine de télécommunication, qu'il s'agisse de la téléphonie mobile, des réseaux sans fils, de la télévision par satellites, ou des applications radar (civiles ou militaires)...etc. est observé. Cet essor considérable a engendré d'énormes besoins et entraîne une évolution technologique majeure au niveau des antennes. Ces dernières doivent faire face aux différentes exigences, à savoir l'augmentation du gain, l'élargissement de la bande passante… et aux différents problèmes existant, à savoir le coût, l’encombrement…etc. Notre objectif est donc de concevoir des topologies d’antennes simples, à faible encombrement et à gain relativement élevé avec un fonctionnement multibande et/ou ultra large bande. Pour cela nous nous sommes orientés vers des antennes à résonateur diélectrique (ARD) dans les bandes UHF et SHF. Récemment, elles ont fait l’objet de plusieurs recherches et ont acquis un grand intérêt du monde académique et industriel. Les ARDs, par leurs simples et diverses géométries, peuvent être alimentées par différentes usuelles techniques. En outre, leurs tailles peuvent être plus petites que leurs homologues à savoir les antennes imprimées. Une première partie de ce travail s’est concentré sur l’étude des ARDs de forme cylindrique, puis une validation de l’outil de simulation par comparaison avec la mesure. En vue d’une utilisation multistandards, d’un élargissement des bandes de fonctionnement ou d’une modification de la fréquence, une seconde partie a été consacrée à l’étude de nouvelles topologies de résonateurs basées sur un empilement vertical et radial de deux cylindres, une topologie en multicouche et en anneau. Les résultats obtenus trouvent leurs applications dans le GSM900-DSC1800, UMTS, WIFI

Desenho de antenas para sensores passivos em materiais não convencionais

Doutoramento em Engenharia EletrotécnicaMotivado pela larga expansão dos sistemas RFID e com o desenvolvimento do conceito de Internet das Coisas, a evolução no desenho e métodos de produção de antenas em suportes de materiais alternativos tem tido uma exploração intensiva nos últimos anos. Isto permitiu, não só o desenvolvimento de produtos no campo da interação homem-máquina, mas também tornar estes produtos mais pequenos e leves. A procura de novas técnicas e métodos para produzir eletrónica impressa e antenas em materiais alternativos e, portanto, uma porta aberta para o aparecimento de novas tecnologias. Isto aplica-se especialmente no mercado dos sensores, onde o peso, o tamanho, o consumo energético, e a adaptabilidade a diversos ambientes, têm grande relevância. Esta tese foca-se no desenvolvimento de antenas com suporte em materiais não convenvionais, como os já testados papel e têxteis, mas também na exploração de outros, desconhecidos do ponto de vista eléctrico, como a cortiça e polímeros biodegradáveis usados em impressão 3D. Estes materiais são portanto usados como substrato, ou material de suporte, para diversas antenas e, como tal, as propriedades electromagnéticas destes materiais têm de ser determinadas. Assim, e apresentado neste documento uma revisão de métodos de caracterização de materiais, bem como a proposta de um método baseado em linhas de trasmissão impressas, e a respectiva caracterização electromagnética de diversos materiais. Além disso, são propostos desenhos de antenas para diversos cenários e aplicações utilizando os materiais anteriormente mencionados. Com esta tese concluiu-se que a utilização de materiais alternativos e hoje uma realidade e os resultados obtidos são muito encorajodares para o desenvolvimento de um conjunto de sensores para aplicações RFID com uma grande capacidade de integração.The advancement of the design and fabrication of antennas using textiles or paper as substrates has rapidly grown motivated by the boom of RFID systems and the developing concept of the Internet of Things. These advancements have allowed, not only the development of products for manmachine interaction, but also to make these products smaller and lighter. The search for new techniques and methods to produce printed electronics and antennas in alternative materials is therefore an open door for new technologies to emerge. Especially in the sensors market, where weight, size, power consumption and the adaptability to the target application, are of great importance. This thesis focuses on the development of antenna design approaches with alternative materials, such as the already tested paper and textiles, but also others relatively unknown, such as cork and biodegradable polymers used in 3D printing. These materials are applied to act as substrates, or support structures for the antennas. Therefore, their electromagnetic properties need to be determined. Due to that, a review of electromagnetic characterization methods, as well as the proposal of a custom method based on printed transmission lines, is presented in this document. Besides, several antenna designs, for di erent application scenarios, using the previously mentioned materials, are proposed. With this thesis it was proved that it is possible to develop passive sensors in di erent alternative materials for RFID applications and others, which shows great promise in the use of these materials to achieve higher integration in sensing and identi cation applications

Ground plane booster antenna technology for wireless handheld devices

This thesis is framed in the field of mobile communications and more particularly in handset antennas. The wireless industry is constantly growing, which entails challenging handset antenna specifications. Handset antennas not only have to be multi-band for satisfying the great number of communication services, but also sufficiently small as for fitting in the reduced space imposed by the handset platforms. The appearance of the MIMO (Multiple Input Multiple Output) technology, further exacerbates these challenges. In order to satisfy these requirements, this thesis proposes the use of the ground plane, inherently present in any handset platform, as the main radiator. Electrically small nonresonant elements, called along this thesis as ground plane boosters, are used to transfer energy to this ground plane. The solution removes the need of including a dedicated antenna featured by considerable dimensions, thus releasing space to integrate other antennas, as well as, other handset components, services and functionalities

Automated design optimisation and simulation of stitched antennas for textile devices

This thesis describes a novel approach for designing 7-segment and 5-angle pocket and collar planar antennas (for operation at 900 MHz). The motivation for this work originates from the problem of security of children in rural Nigeria where there is risk of abduction. There is a strong potential benefit to be gained from hidden wireless tracking devices (and hence antennas) that can protect their security. An evolutionary method based on a genetic algorithm was used in conjunction with electromagnetic simulation. This method determines the segment length and angle between segments through several generations. The simulation of the antenna was implemented using heuristic crossover with non-uniform mutation. Antennas obtained from the algorithm were fabricated and measured to validate the proposed method.This first part of this research has been limited to linear wire antennas because of the wide range and flexibility of this class of antennas. Linear wire antennas are used for the design of high or low gain, broad or narrow band antennas. Wire antennas are easy and inexpensive to build. All the optimised linear wire antenna samples exhibit similar performances, most of the power is radiated within the GSM900 frequency band. The reflection coefficient (S11) is generally better than -10dB. The method of moment (MoM-NEC2) and FIT (CST Studio Suite 2015) solvers were used for this design. MATLAB is used to as an interface to control computational electromagnetic solvers for antenna designs and analysis. The genetic algorithm procedures were written in MATLAB. The second part of the work focuses on meshed ground planes for applications at 900 MHz global system for mobile communications (GSM), 2.45 GHz industrial, scientific, and medical (ISM) band and 5 GHz wearable wireless local area networks (WLAN) frequencies. Square ground planes were developed and designed using linear equations in MATLAB. The ground plane was stitched using embroidery machines. To examine the effect of meshing on the antenna performance and to normalise the meshed antenna to a reference, solid patch antenna was designed, fabricated on an FR4 substrate. A finite grid of resistors was created for numerical simulation in MATLAB. The resistance from the centre to any node of a finite grid of resistors are evaluated using nodal analysis. The probability that a node connects to each node in the grid was computed. The circuit model has been validated against the experimental model by measurement of the meshed ground plane. A set of measurement were collected from a meshed and compared with the numerical values, they show good agreement.</div

A Reflective Electro-Optic Transceiver for Optical RF-Transmission Technology with Multimode Fibers

Künftige hoch entwickelte Kommunikationssysteme sollen nicht nur zuverlässig hohe Datenraten transportieren können. Der zunehmende Bedarf an „überall und zu jeder Zeit“ verfügbaren Datenverbindungen in flexiblen Kommunikationssystemen, mit denen zudem verschiedenste Daten und Services transportiert werden sollen, können durch eine Konvergenz von kabelgebundenen und funkbasierten Systemen gerade in Zugangsnetzen und lokalen Netzwerken befriedigt werden. Aufgrund von geringen Stück- und Installationskosten sowie hohen Bandbreiten ist besonders die Multimodenfaser (MMF) ein viel versprechendes Medium zur Übertragung von Funksignalen speziell in Kurzstrecken-Faser-Funk-Netzwerken. Dabei können neue multifunktionale optoelektronische Bauteile für Systeme mit MMF die Flexibilität und die Konvergenz dieser Netzwerke erhöhen und verbessern. In dieser Dissertation wird ein neuartiger reflektiver elektrooptischer Transceiver (REOT) für die optische Übertragungstechnik mit MMF mit dem Ziel entwickelt, als bidirektionale Komponente schnelle elektro-optische Schnittstellen in MMF-Funk-Basisstationen zu ermöglichen. Als Integration eines wellenlängenselektiven und gezielt transparenten, reflektiven Modulators als Sender (Transmitter) und einer Photodiode als Empfänger (Receiver) wird ein Transceiver realisiert, der im Wellenlängenmultiplex eine zeitgleiche bidirektionale (voll-duplex) Übertragung über nur eine MMF ermöglicht. Der vertikale Aufbau des Transceivers kombiniert die Vorteile einer einfachen Faser-Chip-Kopplung mit einer kostengünstigen Herstellung. Das Design basiert auf Simulationen zum elektro-optischen Verhalten der Schichtstruktur. Der Herstellungsprozess mit photolithographischer Strukturierung und Kontaktierung wird detailliert beschrieben. Der Transceivers wird auf Bauteilebene über die statischen und dynamischen elektrischen und elektro-optischen Eigenschaften sowie in analogen optischen Links mit MMF anhand der Übertragungsfähigkeit des Systems charakterisiert. Auf Grundlage dieser Analysen wird nachgewiesen, dass mit dem Transceiver eine Übertragung standardisierter Funksignale für Zugangsnetze und lokale Netzwerke in Faser-Funk-Systemen mit MMF aus Glas und Polymer unterschiedlicher Längen übertragen werden können. Zudem wird erfolgreich gezeigt, dass auch im passiven Betriebsmodus, d.h. in einem Arbeitspunkt des Elektroabsoptionsmodulators von 0V, viele dieser standardisierten Funksignale mit einem optischen MMF-Übertragungssystem mit REOT optisch übertragen werden können. Darüber hinaus wird die Funktionsweise als Voll-duplex-Transceiver demonstriert. Vorausblickend wird ein Einbau des REOTs in eine LTCC-basierte Basisstation konzipiert.Future advanced communication systems are not only expected to provide high bit rates and reliability. With the increasing demand for “everywhere and anytime” available data connec-tion and on communication systems being highly flexible and capable of transmitting multi-service data, the convergence of fixed and wireless communication systems for access and local area networks is supposed to satisfy these demands. Due to low component and installa-tion costs together with high available bandwidth, especially multimode fiber (MMF) optic systems show promise on transmitting radio signals and serving wireless base stations in short range fiber wireless infrastructure. In particular novel multi-functional optoelectronic devices especially designed for MMF systems will enhance the system flexibility and this conver-gence. In this dissertation a unique reflective electro-optic transceiver (REOT) for optical transmis-sion technology using MMFs is developed with the scope of creating a bi-directional compo-nent for high-speed opto-electrical interfaces such as MMF-wireless base stations. By verti-cally integrating a wavelength selective and partially transparent reflective modulator as transmitter and a photodiode as receiver, the sophisticated transceiver is designed for wave-length division multiplexing (WDM) technique and enables full-duplex transmission – namely bi-directional transmission at the same time – via only one MMF. The vertical integration of the transceiver combines the advantages of easy fiber-chip coupling and low-cost fabrication. The transceiver layout is based on simulations of the layer structure and its resulting electro-optical response. The fabrication process containing the photolithographic structuring and contacting is described in detail. The transceiver is being characterized in terms of the static and dynamic electrical and electro-optical properties and its performance in analog optical links using MMF. Based on these analyses the transceiver is used in radio-over-fiber (RoF) systems with various types and lengths of multimode glass and polymer optical fibers demonstrating its capability of trans-mitting standard wireless access and local area network signals. It is successfully shown that even in passive operation mode at an operating point of 0 V bias voltage of the electro-absorption modulator various wireless standard signals can optically be transmitted using the REOT in a MMF transmission system. In addition, the full-duplex functionality of the REOT is demonstrated. And finally, an assembly of the transceiver into new LTCC-based fiber-wireless base stations is envisaged