A reconfigurable radio-frequency converter IC in 0.18 µm CMOS

This work presents a reconfigurable RF converter for DVB-T television applications using triple-play over GPON. The system takes the DVB-T input, a wavelength division multiplexing (WDM) signal with spectral inversion in the range from 47 MHz to 1000 MHz, up-converts its frequency to the band-pass of a highly selective surface-acoustic wave (SAW) filter centered at 1.3 GHz, and then down-converts it so that it is compatible with the antenna input of conventional television sets. The designed RF converter incorporates two pairs of frequency synthesizer and mixer, based, respectively, on an integer-N phase-locked loop (PLL) with two LC-tank VCOs with 128 coarse tuning bands in the range from 1.35 GHz to 2.7 GHz, and a double-balanced Gilbert cell, modified for better impedance matching and improved linearity. It is fed with regulated supplies compensated in temperature and programmed by an I2 C interface operating on five 16-bit registers. This work presents the experimental characterization of the whole system plus selected cells for stand-alone testing, which have been fabricated in a 0.18 µm CMOS process

The Photostroller: supporting diverse care home residents in engaging with the world

The Photostroller is a device designed for use by residents of a care home for older people. It shows a continuous slideshow of photographs retrieved from the FlickrTM image website using a set of six predefined categories modified by a tuneable degree of ‘semantic drift’. In this paper, we describe the design process that led to the Photostroller, and summarise observations made during a deployment in the care home that has lasted over two months at the time of writing. We suggest that the Photostroller balances constraint with openness, and control with drift, to provide an effective resource for the ludic engagement of a diverse group of older people with each other and the world outside their home

TechNews digests: Jan - Nov 2008

TechNews is a technology, news and analysis service aimed at anyone in the education sector keen to stay informed about technology developments, trends and issues. TechNews focuses on emerging technologies and other technology news. TechNews service : digests september 2004 till May 2010 Analysis pieces and News combined publish every 2 to 3 month

Design And Implementation Of A Low-cost, Compact And Long Range Monostatic Uhf Rfid Reader With Read Point Extension

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2014Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2014RFiD sistemlerinin çeşitli uygulama alanlarında artan popülerliği neticesinde, özelikle UHF bandında çalışacak olan RFiD okuyucu üretimine dair ihtiyaçlar gittikçe artan bir eğilim göstermektedir. Bahsedilen ihtiyaçlar göz önüne alınarak, bu tez kapsamında yeni bir okuyucu tasarımı gerçekleştirilmiştir. Tasarlanan okuyucu, endüstriyel RFiD uygulamaları için gerekli görülen birçok ilgi çekici özelliği bünyesinde barındırmaktadır. RFiD sistemleri, kısaca radyo frekanslı kimliklendirme diye tanımlanabilmektedir. Elektromanyetik dalgaları kullanarak (kablosuz iletişim), üzerlerine RFiD etiketleri iliştirilmiş olan nesne, hayvan ve insanlardan verilerin transfer edilmesini sağlarlar. Takip, gözlem, kontrol vb. amaçlı kullanılabilmektedir. Genel itibari ile barkod sistemi gibi otomatik tanımlama teknolojileri ailesinin bir üyesidir. Tez kapsamındaki ilk iki bölümde, RFiD sisteminin detaylarına ve temel standartlarına dair bilgilere yer verilmiştir. Üçüncü bölümde, donanım sistem tasarımına ait süreçler detaylı bir şekilde ele alınmış ve simülasyon ile ölçüm sonuçlarına yer verilmiştir. Tasarlanan okuyucu; okuma noktası artırılmış, düşük maliyetli, kompakt, uzun menzilli ve Gen2 uyumlu olacak şekilde UHF bandında geliştirilmiştir. Aynı zamanda, birden fazla okuyucunun aynı anda çalıştığı yoğun ortamlarda çalışabilme özelliğine sahiptir. Okuyucu, anten çıkış gücü 30-dBm olan iki adet anten çıkış portu barındırmaktadır. Ayrıca, yenilikçi bir özellik olarak, geri yansıyan RF gücünü azaltmak için anten uydurma devresi tasarlanmıştır. Bu işlem, okuyucunun çıkış empedansının antenin empedansına uydurulması ile gerçekleştirilmektedir. Bununla birlikte, okuyucu, işlem anında antenin empedansını olası çevresel faktörlere karşı kararlı bir yapıda tutabilme kabiliyetine de sahiptir. Bunların yanı sıra, bir güç algılayıcı devresi vasıtasıyla, okuyucu için var olan yasal koşulları sağlamak adına, çıkış gücünü sınırlandırma ve kontrol etme özellikleri de mevcuttur. Donanım tasarımı esnasında, yüksek frekansta PCB tasarım teknikleri, radyo frekansı ve fizik temelleri, dijital ve analog devre tasarım teknikleri gibi farklı disiplinlerden çeşitli teknik bilgiler ve kabiliyetler kullanılmıştır. Artırılmış okuma noktası özelliği, tasarlanan bir başka donanım, RF çoklayıcı devresi, vasıtası ile sağlanmaktadır. Bu ürün sayesinde, UHF RFiD okuyucunun anten çıkışları artırılarak sistem kurulum maliyeti azaltılmaktadır. Bu cihazın amacı, çoklu anten ihtiyacı olan uygulamalarda okuyucu sayısını sabit tutarak, anten çıkış sayısını artırmaktır. Bu sayede sistemin uygulanma maliyetinde avantaj sağlanmaktadır. Ürün dahilindeki anahtarlama entegrelerinin araya girme kayıplarının az olması ve entegrelerin kontrolünü sağlayan denetleyici yapısı, okuyucuların marka modelinden bağımsız tak-çalıştır sistem modeli ürüne ait katma değerli nitelikleridir. Bu tez dahilinde tasarımı gerçekleştirilen UHF RFiD okuyucu, aynı zamanda Bilim, Sanayi ve Teknoloji Bakanlığı’nın sağlamış olduğu Ar-Ge proje destekleri kapsamında desteklenmiştir. Bu proje ve tez neticesinde, imalat masraflarını düşürmek adına okuyucu tasarımı ve üretimi yerli olarak gerçekleştirilmiş ve yurt içinde milli bir cihaz geliştirilmiştir. Proje sonucunda, başlangıçta belirlenen tüm kıstaslar başarıyla sağlanmış ve birer adet RF çoklayıcı devresi ve UHF RFiD okuyucu devresi, kontrol ünitesi ve grafiksel arayüz yazılımı ile birlikte, istenen herhangi bir RFiD uygulamasında kullanılmak üzere prototip olarak üretilmiştir.RFiD systems have an increasing popularity in various kinds of applications. Necessities are rising for the manufacture of new RFiD readers in industry especially at UHF band. Based on this concept, a new UHF RFiD reader design with extended read point capability has been presented within the scope of this thesis. Designed reader has attractive features required by some industrial RFiD applications. Before the hardware design part of the study, first, the background of RFiD and its key standards have been introduced in the first two chapters. In the third chapter, the hardware design process has been covered in detail and simulation and measurement results have been presented. The designed hardware is a low-cost, compact and long-range Gen2 compliant UHF RFiD reader with extended read point capability. The reader has up to 30 dBm (1 Watt) output RF power at two selectable antenna ports. The reader has an antenna tuning circuit, a novel feature, to reduce reflected RF power from antennas. This is achieved by tuning output impedance of the reader to the impedance of antenna. The reader can also tune the antenna impedance during operation in case the environment of the antenna changes. A power detector is used to control and limit the output power to regulatory requirements. While designing the hardware, several technical skills within a wide spectrum of disciplines were used like PCB design in high frequency, radio frequency, physics of RF, digital and analog design. Extended read point capability is provided with another hardware design called RF multiplexer circuit. This product has been designed in order to increase the number of antenna output ports of UHF RFiD reader to reduce the system implementation cost in dense antenna applications. This hardware design is also a part of another Research & Development project funded by the Ministry of Science, Industry and Technology of Turkey. As a part of this project and this thesis, the UHF RFiD reader has been designed as a domestic product to lower the cost of manufacture. As a result of this project, all the objectives have been achieved and a prototype of UHF RFiD reader, which has a control unit and a graphical user interface, and an RF multiplexer have been manufactured to be used in any desired UHF RFiD application.Yüksek LisansM.Sc

Ifaces: Adaptative user interfaces for ambient intelligence

Proceedings of the IADIS International Conference on Interfaces and Human Computer Interaction. Amsterdam, The Netherlands 25-27 July 2008In this paper we present an ontology language to model an environment and its graphical user interface in the field of ambient intelligence. This language allows a simple definition of the environment and automatically produces its associated interaction interface. The interface dynamically readjusts to the characteristics of the environment and the available devices. Therefore it adapts to the necessities of the people who have to use it and their resources. The system has been developed and tested employing a real ambient intelligence environment.This work has been partly funded by HADA project number TIN2007 – 64718 and the UAM – Indra Chair in Ambient Intelligence

Application of Things: A Step beyond Web of Things

Internet of Things has achieved a great expectation in the last few years, largely due to possibilities in the field of the interaction between user and environment. This interaction allows users to get involved in their environments, managing at all times each item that surrounds them. Specially, because of complex services delivered by surrounding item, increasingly it is necessary to help users to choose what services are offered and what are theirs functionalities. Is this paper, is presented a new approach to the human-items interaction by using the concept of Internet of Things. In this way, the user can not only run the different applications offers by smart-things, but to share theirs results through many social networks and allows the remote execution of services provided by the own user and his/her social environment. Furthermore, a structure will be defined to assure the best user comfort when information sharing between the device and the environments was needed.Ministerio de Ciencia e Innovación TIN2009-14378-C02-0

Emerging research directions in computer science : contributions from the young informatics faculty in Karlsruhe

In order to build better human-friendly human-computer interfaces, such interfaces need to be enabled with capabilities to perceive the user, his location, identity, activities and in particular his interaction with others and the machine. Only with these perception capabilities can smart systems ( for example human-friendly robots or smart environments) become posssible. In my research I\u27m thus focusing on the development of novel techniques for the visual perception of humans and their activities, in order to facilitate perceptive multimodal interfaces, humanoid robots and smart environments. My work includes research on person tracking, person identication, recognition of pointing gestures, estimation of head orientation and focus of attention, as well as audio-visual scene and activity analysis. Application areas are humanfriendly humanoid robots, smart environments, content-based image and video analysis, as well as safety- and security-related applications. This article gives a brief overview of my ongoing research activities in these areas

MEMS Tunable Frame Antennas Enabling Carrier Aggregation at 600 MHz

The goal of this paper is to propose a tunable antenna system, that aims to cover the LTE low band (699–960 MHz), medium band (1710–2100 MHz) and high band (2100–2690 MHz), as well as the 600 MHz bands by tuning. The architecture consists of four multiband antennas, made up of different radiators, placed in the frame of the mobile handset at the optimized distance of 0.5 mm from each other. Simulations including MEMS tunable capacitors prove that, it is possible to reconfigure the dual resonance in low band, without deteriorating the antennas performance. The tuning ability of the fabricated structure is tested with the PNA and measurements of the total efficiency are performed in the MVG SG24. The results of the measurements are in accordance with the simulations and confirm that the operating frequency of the proposed frame antenna array in low band can be tuned down to the starting point of band 71, with a −6 dB impedance bandwidth of 32 MHz, without altering the antennas behaviour in medium and high band. The resulting peak value of the total efficiency of −5.3 dB at 615 MHz is acceptable, considering the mobile phones in the market. Moreover, the analysis of the user effects, carried out via simulations both in data and in talk mode, reveals a reduced total efficiency of 4 and 8 dB on average, due to the user hand and the user hand-head respectively, compared with the performance in free space

A Primer on Software Defined Radios

The commercial success of cellular phone systems during the late 1980s and early 1990 years heralded the wireless revolution that became apparent at the turn of the 21st century and has led the modern society to a highly interconnected world where ubiquitous connectivity and mobility are enabled by powerful wireless terminals. Software defined radio (SDR) technology has played a major role in accelerating the pace at which wireless capabilities have advanced, in particular over the past 15 years, and SDRs are now at the core of modern wireless communication systems. In this paper we give an overview of SDRs that includes a discussion of drivers and technologies that have contributed to their continuous advancement, and presents the theory needed to understand the architecture and operation of current SDRs. We also review the choices for SDR platforms and the programming options that are currently available for SDR research, development, and teaching, and present case studies illustrating SDR use. Our hope is that the paper will be useful as a reference to wireless researchers and developers working in the industry or in academic settings on further advancing and refining the capabilities of wireless systems