Printable windscreen quad-band GSM antenna

The design and simulation of a suitable GSM antenna for integration with the rear windscreen of a car is presented in this paper. A bent asymmetric dipole antenna was chosen to minimise the surface area and thus cause minimal effect to the aesthetics of the car as well as to the driver’s visibility. The antenna has been simulated on a realistic three-layered windscreen. Parasitics were added to the design to improve the bandwidth at 900 and 1800MHz at both European and American bands. The bent asymmetric dipole was advantageous compared to a straight asymmetric dipole because i) the radiation pattern was more omnidirectional and ii) the parasitics at each band could be designed to work independently of each other

UWB PIFA Antenna for Simplified Transceivers

A planar inverted-F antenna (PIFA) with an input match designed to offer the capability of a front-end bandpass filter in mobile communication transceivers is presented. The proposed antenna is low cost, easily fabricated, and operates in the unlicensed lower band (3.168– 4.752 GHz) of the ultra-wideband (UWB) communication standard with a 3.57:1 VSWR. It is demonstrated that the antenna possesses a radiation pattern with good front-to-back ratio and shows acceptable impedance matching in proximity to large ground planes making it suitable for applications such as in-vehicle communications

Inkjet printed and folded LTE antenna for vehicular application

A multi-band antenna suitable for Long-term Evolution (LTE) is inkjet-printed, and then folded around a cylindrical form. The plastic cylinder is also printed using additive manufacturing techniques, as a separate process. The antenna is based on a planar wideband monopole radiator concept with an additional resonator for the LTE700 frequency band. The aim is to study the potential of low-cost additive manufacturing (AM) techniques for the development of vehicular antennas. Two antennas have been fabricated, one on paper substrate, and a second on polyethylene terephthalate (PET) substrate. The one on paper is tested as a planar monopole antenna on a large ground plane. The one printed on PET is shaped onto the cylindrical form. The main aim is to investigate the use of low-cost inkjet printing techniques for the fabrication of disposable vehicular antennas that can be upgraded regularly. The antennas successfully operate at all LTE and mobile frequency bands. Finite different time domain simulations compare well with measurements

Compact multiband antennas for wireless systems

The research work to be presented focuses on the study of multiband antennas for wireless indoor communications and wearable transceivers. An introduction to the essential antenna parameters and the theory behind the electromagnetic simulators used for this research sets the background necessary for understanding the procedure used when designing and measuring antennas. A study of the characteristics of textile materials at microwave frequencies using non-resonant transmission methods is later performed. The basis of small antenna design by top loading and the design of the Planar Inverted F Antenna is also covered. The main research work is divided into two parts. The first part investigates antennas for mobile and wireless indoor communications networks. The antennas are intended for Distributed Antenna Units to be located in buildings. A dual band Planar Inverted F antenna previously developed at the University of Kent is chosen as the prototype to achieve multiband and broadband operations. A parasitic resonator on the ground plane and side resonators are introduced in a study where additional bands are added. The derivation of equivalent function planar antennas from three dimensional multiband PIFAs is also covered. The second part of the work focus on antennas for wearable applications. The antennas are intended for WLAN on-body communication networks. A novel approach is taken by using metallic button structures to create wearable antennas. Dual frequency band operation is achieved on the button structures by adding a metallic plate on the top of the antenna and a cylindrical via connector. Miniaturization techniques are later applied to the button structure to reduce the size of the antenna while maintaining a match at the 2.4GPIz and 5 GHz wireless bands

RF Modelling and Characterization of Tyre Pressure Sensors and Vehicle Access Systems

Core topics of the work are the vehicle access systems such as PAssive Start and Entry (PASE), Remote Keyless Entry (RKE) as well as Tyre Pressure Monitoring System (TPMS). Two goals are followed: the development of antennas and functionality analysis from RF (Radio Frequency) point of view and improvement of system parts. The overall objective of this work is to advance the state-of-the-art vehicular electromagnetic simulation taking into account the vehicle body and nearest surroundings

Moniantennijärjestelmät autoympäristössä

MIMO systems have emerged in the last few years as a means to improve the quality of service and spectral efficiency of wireless communication systems. This thesis examines the use of multi-antenna systems on vehicles. The main objectives of this thesis are to develop a procedure for the design of multi-antenna systems, compare the benefits of different multi-antenna systems in automotive environment, study the suitability of the chosen electromagnetic simulation method to modelling and simulation of automotive antennas, and also to give ample references for the reader, in case a more in-depth understanding in the areas of multi-antenna techniques and automotive antennas is needed. The electromagnetic simulation of the antenna systems are based on the finite integration technique with commercial software, while link level performance simulation is performed on a MATLAB implementation of the SCME radio channel model. The finite integration technique is found to provide accurate radiation pattern results, and it can be recommended for the purpose of simulation of automotive antenna systems at the 700 MHz carrier frequency. On link level simulations the focus is on simulating 2×2 multiantenna systems. These simulations imply a noticeably improved BER when a BF MIMO system is employed, compared to the traditional MIMO system. The BF MIMO is a new concept that combines the best sides of beamforming and MIMO. This is the first study where the BF MIMO concept is applied to antennas in automotive environment. The results for the different antenna array configurations were indeterminate. In general, it can be said that the radio channel (or channel model) is one of the most significant factors in determining the performance of a multi-antenna systems, and it is highly unlikely that any single array configuration can provide optimal performance in every channel conditions. The first part of this thesis, Chapters 2 and 3, provides background of multi-antenna systems. Theoretical concepts of multi-antenna systems are introduced in Chapter 2 to enable the analysis of such systems. In the third chapter, a literature survey is presented as a summary of related studies on the areas of automotive antennas, multi-antenna systems, related information theory and electromagnetic simulation methods of antennas. In the latter part of this thesis, Chapter 4 describes the electromagnetic and link level simulation software packages and the simulation of the antennas. The results are presented in Chapter 5, and conclusions are drawn in Chapter 6. /Kir1

Positioning of a wireless relay node for useful cooperative communication

Given the exorbitant amount of data transmitted and the increasing demand for data connectivity in the 21st century, it has become imperative to search for pro-active and sustainable solutions to the effectively alleviate the overwhelming burden imposed on wireless networks. In this study a Decode and Forward cooperative relay channel is analyzed, with the employment of Maximal Ratio Combining at the destination node as the method of offering diversity combining. The system framework used is based on a three-node relay channel with a source node, relay node and a destination node. A model for the wireless communications channel is formulated in order for simulation to be carried out to investigate the impact on performance of relaying on a node placed at the edge of cell. Firstly, an AWGN channel is used before the effect of Rayleigh fading is taken into consideration. Result shows that performance of cooperative relaying performance is always superior or similar to conventional relaying. Additionally, relaying is beneficial when the relay is placed closer to the receiver

Passive Planar Microwave Devices

The aim of this book is to highlight some recent advances in microwave planar devices. The development of planar technologies still generates great interest because of their many applications in fields as diverse as wireless communications, medical instrumentation, remote sensing, etc. In this book, particular interest has been focused on an electronically controllable phase shifter, wireless sensing, a multiband textile antenna, a MIMO antenna in microstrip technology, a miniaturized spoof plasmonic antipodal Vivaldi antenna, a dual-band balanced bandpass filter, glide-symmetric structures, a transparent multiband antenna for vehicle communications, a multilayer bandpass filter with high selectivity, microwave planar cutoff probes, and a wideband transition from microstrip to ridge empty substrate integrated waveguide

Ubiquitous computing and natural interfaces for environmental information

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do Grau de Mestre em Engenharia do Ambiente, perfil Gestão e Sistemas AmbientaisThe next computing revolution‘s objective is to embed every street, building, room and object with computational power. Ubiquitous computing (ubicomp) will allow every object to receive and transmit information, sense its surroundings and act accordingly, be located from anywhere in the world, connect every person. Everyone will have the possibility to access information, despite their age, computer knowledge, literacy or physical impairment. It will impact the world in a profound way, empowering mankind, improving the environment, but will also create new challenges that our society, economy, health and global environment will have to overcome. Negative impacts have to be identified and dealt with in advance. Despite these concerns, environmental studies have been mostly absent from discussions on the new paradigm. This thesis seeks to examine ubiquitous computing, its technological emergence, raise awareness towards future impacts and explore the design of new interfaces and rich interaction modes. Environmental information is approached as an area which may greatly benefit from ubicomp as a way to gather, treat and disseminate it, simultaneously complying with the Aarhus convention. In an educational context, new media are poised to revolutionize the way we perceive, learn and interact with environmental information. cUbiq is presented as a natural interface to access that information