Local positioning with sensor-enabled passive multistandard RFID transponders

RFID is used today in many fields of every day life like access control, anti-theft protection or logistics. Within this article a short overview of the basic RFID principles and the EPC protocol flow is given at first. Afterwards new design approaches for RFID systems within the scope of the research project RFID-S are presented

Switchable wideband receiver frontend for 5G and satellite applications

Modern day communication architectures provides the requirement for interconnected devices offering very high data rate (more than 10 Gbps), low latency, and support for multiple service integration across existing communication generations with wideband spectrum coverage. An integrated satellite and 5G architecture switchable receiver frontend is presented in this thesis, consisting of a single pole double throw (SPDT) switch and two low noise amplifiers (LNAs) spanning X-band and K/Ka-band frequencies. The independent X-band LNA (8-12 GHz) has a gain of 38 dB at a centre design frequency of 9.8 GHz, while the K/Ka-band (23-28 GHz) has a gain of 29 GHz at a centre design frequency of 25.4 GHz. Both LNAs are a three-stage cascaded design with separated gate and drain lines for each transistor stage. The broadband high isolation single pole double throw (SPDT) switch based on a 0.15 μm gate length Indium Gallium Arsenide (InGaAs) pseudomorphic high electron transistor (pHEMT) is designed to operate at the frequency range of DC-50 GHz with less than 3 dB insertion loss and more than 40 dB isolation. The switch is designed to improve the overall stability of the system and the gain. A gain of about 25 dB is achieved at 9.8 GHz when the X-band arm is turned on and the K/Ka-band is turned off. A gain of about 23 dB is achieved at 25.4 GHz when the K/Ka-band arm is turned on and the X-band arm is off. This presented switchable receiver frontend is suitable for radar applications, 5G mobile applications, and future broadband receivers in the millimetre wave frequency range

Integrated transmitter circuit for multiport reconfigurable antenna

This master’s thesis was a part of an academic research projecta where the target is to design an integrated circuit (IC) to dynamically tune the operating frequency of a transmitter antenna. A multiport antenna model was provided by Prof. Viikari’s group who recently presented a novel idea of multiport antenna tuning. In this concept the multiport antenna feeds are excited with weighted signals having certain amplitudes and phases, thus leading to antenna tuning at the desired operating frequency. However, it is not feasible to dynamically scale the antenna feeding signal amplitudes and phases with discrete electronics. Therefore, the system on chip solution (SoC) approach was studied in this thesis. Initially, the concept was studied on theoretical level and with circuit simulations. The tuning analysis framework was developed to scrutinize the antenna weighted signal characteristics. This analysis provides the two most important specifications for the IC i.e., the accuracy required for on-chip amplitude and phase tuning. For the antenna under consideration, the on chip phase and amplitude tuning system have 6 bit and 3 bit scaling resolutions respectively. The tuning system is designed for a 4-port reconfigurable antenna where each antenna feed has a separate phase tuning and amplitude tuning block. The tuning system was simulated along the 4-port antenna at 2 GHz, and the simulation result validates the multiport tuning concept. This novel integrated tuning system is scalable as well as capable of tuning any reconfigurable multiport antenna

Design of antenna array and data streaming platform for low-cost smart antenna systems

The wide range of wireless infrastructures such as cellular base stations, wireless hotspots, roadside infrastructures, and wireless mobile infrastructures have been increasing rapidly over the past decades. In the transportation sector, wireless technology refreshes require constantly introducing newer wireless standards into the existing wireless infrastructure. Different wireless standards are expected to co-exist, and the air space congestion worsens if the wireless devices are operating in different wireless standards, where collision avoidance and transmission time synchronisation become complex and almost impossible. Huge challenges are expected such as operation constraints, cross-system interference, and air space congestion. Future proof and scalable smart wireless infrastructures are crucial to harmonise the un-coordinated wireless infrastructures and improve the performance, reliability, and availably of the wireless networks. This thesis presents the detailed design of a novel pre-configurable smart antenna system and its sub-system including antenna element, antenna array, and radio frequency (RF) frontend. Three types of 90° beamforming antenna array (with low, middle and high gain) were designed, simulated, and experimentally evaluated. The RF frontend module or transmit and receive (T/R) module was designed and fabricated. The performance of the T/R module was characterised and calibrated using the recursive calibration method, and drastic sidelobe level (SLL) improvement was achieved using the amplitude distribution technique. Finally, the antenna arrays and T/R modules are integrated into the pre-configurable smart antenna system, the beam steering performance is experimentally evaluated and presented in this thesis. With the combination of practical know-how and theoretical estimation, the thesis highlights how the modern smart antenna techniques that support most cutting-edge wireless technology can be adopted into the existing infrastructure with minimum distraction to the existing systems. This is in line with the global Smart City initiative, where a huge number of Internet of Things (IoT) devices being wired, or wireless are expected to work harmoniously in the same premises. The concept of the pre-configurable smart antenna system presented in this thesis is set to deliver a future-proof and highly scalable and sustainable infrastructure in the transportation market

A comprehensive survey of wireless body area networks on PHY, MAC, and network layers solutions

Recent advances in microelectronics and integrated circuits, system-on-chip design, wireless communication and intelligent low-power sensors have allowed the realization of a Wireless Body Area Network (WBAN). A WBAN is a collection of low-power, miniaturized, invasive/non-invasive lightweight wireless sensor nodes that monitor the human body functions and the surrounding environment. In addition, it supports a number of innovative and interesting applications such as ubiquitous healthcare, entertainment, interactive gaming, and military applications. In this paper, the fundamental mechanisms of WBAN including architecture and topology, wireless implant communication, low-power Medium Access Control (MAC) and routing protocols are reviewed. A comprehensive study of the proposed technologies for WBAN at Physical (PHY), MAC, and Network layers is presented and many useful solutions are discussed for each layer. Finally, numerous WBAN applications are highlighted

Design and analysis of multi-element antenna systems and agile radiofrequency frontends for automotive applications

Vehicular connectivity serves as one of the major enabling technologies for current applications like driver assistance, safety and infotainment as well as upcoming features like highly automated vehicles - all of which having certain quality of service requirements, e. g. datarate or reliability. This work focuses on vehicular integration of multiple-input-multiple-output (MIMO) capable multielement antenna systems and frequency-agile radio frequency (RF) front ends to cover current and upcoming connectivity needs. It is divided in four major parts. For each part, mostly physical layer effects are analyzed (any performance lost on physical layer, cannot be compensated in higher layers), sensitivities are identified and novel concepts are introduced based on the status-quo findings.Fahrzeugvernetzung dient als eine der wesentlichsten Befähigungstechnologien für moderne Fahrerassistenzsysteme und zukünftig auch hochautomatisiertes Fahren. Sowohl die heutigen als auch zukünftige Anwendungen haben besondere Dienstgüteanforderungen, z.B. in Bezug auf die Datenrate oder Verlässlichkeit. Im Rahmen dieser Arbeit wird die Integration von Mehrantennensystemen für MIMO-Funkanwendungen (MIMO: engl. Multiple Input Multiple Output) sowie von frequenzagilen Hochfrequenzfrontends im Fahrzeugumfeld untersucht, um so eine technische Grundlage für zukünftige Anforderungen an die automobile Vernetzung anbieten zu können. Die dabei gewonnenen Erkenntnisse lassen sich in vier Teile gliedern. Grundsätzlich konzentrieren sich die Untersuchungen vorrangig auf die physikalische Ebene. Auf Basis des aktuellen Status Quo werden Sensitivitäten herausgearbeitet, neue Konzepte hergeleitet und entwickelt

Sistema de radar distribuído baseado em fibra ótica

The Radar technology has been presented as a promising solution to the demanding challenges of the modern society, mainly due to its exibility and non-invasiveness, making it suitable for a wide range of useful applications. This dissertation addresses the development and testing of a distributed Radar system with a central processor and radio-over- bre signal transport. In this scope, besides analysing di erent waveforms suitable to be implemented (namely, OFDM and FMCW), a simulator capable of evaluate the relationship between a system con guration/parametrization and its performance was also developed. Additionally, the whole system was engineered, including some modules already developed in the scope of the RETIOT project and others developed, tested and analysed within the scope of this work. Finally, some preliminary testing was made, including the system behavior estimation.A tecnologia Radar tem surgido como uma solução promissora para os novos desafios da sociedade moderna, maioritariamente por ser uma tecnologia flexível e não invasiva, tornando-a assim adequada para uma grande série de aplicações. Esta dissertação aborda um sistema de Radar distribuído com processamento centralizado e distribuição analógica de rádio-sobre-fibra. Neste contexto, para além de ser feita uma análise a diferentes tipos de onda possíveis de implementar, foi também desenvolvido um simulador que permitiu interpretar a relação que a disposição dos elementos do sistema têm na sua performance. Adicionalmente, foi desenvolvida toda a arquitetura do sistema, que inclui alguns módulos previamente desenvolvidos no âmbito do projeto RETIOT, e outros desenvolvidos testados e analisados na esfera deste trabalho. Por _m, foram feitos alguns testes preliminares ao sistema e uma estimativa do seu comportamento como um todo.Mestrado em Engenharia Eletrónica e Telecomunicaçõe