Compact and Efficient Millimetre-Wave Circuits for Wideband Applications

Radio systems, along with the ever increasing processing power provided by computer technology, have altered many aspects of our society over the last century. Various gadgets and integrated electronics are found everywhere nowadays; many of these were science-fiction only a few decades ago. Most apparent is perhaps your ``smart phone'', possibly kept within arm's reach wherever you go, that provides various services, news updates, and social networking via wireless communications systems. The frameworks of the fifth generation wireless system is currently being developed worldwide. Inclusion of millimetre-wave technology promise high-speed piconets, wireless back-haul on pencil-beam links, and further functionality such as high-resolution radar imaging. This thesis addresses the challenge to provide signals at carrier frequencies in the millimetre-wave spectrum, and compact integrated transmitter front-ends of sub-wavelength dimensions. A radio frequency pulse generator, i.e. a ``wavelet genarator'', circuit is implemented using diodes and transistors in III--V compound semiconductor technology. This simple but energy-efficient front-end circuit can be controlled on the time-scale of picoseconds. Transmission of wireless data is thereby achieved at high symbol-rates and low power consumption per bit. A compact antenna is integrated with the transmitter circuit, without any intermediate transmission line. The result is a physically small, single-chip, transmitter front-end that can output high equivalent isotropically radiated power. This element radiation characteristic is wide-beam and suitable for array implementations

Wireless sensor networks for flight applications

Die Prognosen der Marktentwicklung im Luftfahrtbereich sehen sehr positiv aus. In den kommenden 20 Jahren soll sich die Anzahl der Passagierflugzeuge verdoppeln, was sicherlich die Geschäfte im Luftfahrtbereich anregen wird. Jedoch bildet sich neue Konkurrenz in Asien, welche den Wettbewerb erhöhen wird. Um in dieser neuen Marktsituation weiterhin bestehen zu können, müssen Flugzeughersteller vermehrt innovative Flugzeugkonzepte entwickeln, mit welchen sie sich von ihren Konkurrenten absetzen können. Die meisten Innovationen zielen auf eine Reduzierung des Gewichts und auf höhere Energieeffizienz von Flugzeugen ab. Ebenso steht eine Reduzierung der Inbetriebnahme- und Betriebskosten im Fokus. Ein vielversprechender Ansatz diese Ziele zu erreichen, ist der Einsatz von drahtlosen Sensornetzen, um Luftfahrtanwendungen anzubinden. Der Einsatz so eines drahtlosen Sensornetzes kann in vielerlei Hinsicht Nutzen bringen. Verkabelung kann eingespart werden was große Gewichtsreduktionen mit sich bringt. Arbeitsabläufe können verbessert werden, wodurch Inbetriebnahme- und Betriebskosten reduziert werden können. Zusätzlich kann der Einsatz von drahtlosen Sendernetzen dazu beitragen, bisher nicht sinnvoll realisierbare Anwendungen einzuführen, beziehungsweise diese erst zu ermöglichen. In dieser Arbeit werden typische Flugzeuganwendungen identifiziert, welche von dem Einsatz eines drahtlosen Sendernetzes profitieren können. Die Herausforderungen, die der Einsatz so eines drahtlosen Sensornetzes hervorruft, werden beleuchtet, als auch entsprechende Technologien und Protokolle vorgestellt, welche darauf abzielen, diesen Herausforderungen zu begegnen.The market forecast for aircraft manufacturers is very promising; the fleet of passenger aircraft will double. This will clearly generate a strong business for aircraft manufactures. But new competitors arise and, hence, rivalry is increasing. To succeed in this market situation, aircraft manufacturers have to build innovative aircraft to set themselves apart from competitors. Most of the research effort is concentrated on developing lighter, more energy-efficient aircraft which reduce operational costs for airline operators. A very promising approach to accomplish this goal is to introduce wireless sensor networks for flight applications. Such wireless sensor networks can be very beneficial: they can help to reduce weight by saving cabling, they can improve workflows and, hence, reduce commissioning and operational costs, and they can enable new applications which were not feasible or even possible before.In this work, flight applications are investigated to identify the challenges which arise when introducing such a wireless sensor network. Technologies and protocols are presented which aim to tackle these challenges. In particular, the most demanding prerequisites are energy efficiency, transmission reliability, scalability, synchronization, and localization. Four of these demands will be addressed by three different protocols. First, a clock synchronization protocol is presented which uses a special hardware devicea wake-up receiverto achieve synchronization in a very energy-efficient, reliable, and scalable way. Second, using this same technology a clustering protocol is presented which can reduce redundant transmissions. In doing so, it becomes possible to lower the mean energy consumption for hundreds of sensor nodes. Last, a custom-tailored medium access protocol is presented which utilizes spatial diversity to increase transmission reliability while keeping a very low power demand.Tag der Verteidigung: 25.08.2015Paderborn, Univ., Diss., 201

Integrated Circuits and Systems for Smart Sensory Applications

Connected intelligent sensing reshapes our society by empowering people with increasing new ways of mutual interactions. As integration technologies keep their scaling roadmap, the horizon of sensory applications is rapidly widening, thanks to myriad light-weight low-power or, in same cases even self-powered, smart devices with high-connectivity capabilities. CMOS integrated circuits technology is the best candidate to supply the required smartness and to pioneer these emerging sensory systems. As a result, new challenges are arising around the design of these integrated circuits and systems for sensory applications in terms of low-power edge computing, power management strategies, low-range wireless communications, integration with sensing devices. In this Special Issue recent advances in application-specific integrated circuits (ASIC) and systems for smart sensory applications in the following five emerging topics: (I) dedicated short-range communications transceivers; (II) digital smart sensors, (III) implantable neural interfaces, (IV) Power Management Strategies in wireless sensor nodes and (V) neuromorphic hardware

Design & implementation of low power MAC protocol for wireless body area network.

Ph.DDOCTOR OF PHILOSOPH

Design of an Integrated CMOS Transceiver with Wireless Power and Data Telemetry with Application to Implantable Flexible Neural Probes

Recent developments in implantable medical devices (IMDs) have created a need for communication systems integrated directly into the implant with feedback data for various sensing systems. The need for modern communication techniques, power delivery systems, and usable interfaces for smart implants present an interesting challenge for engineers trying to provide doctors and medical professionals with the best resources available for medical research. This dissertation will cover the design of an integrated CMOS transceiver and near-field inductive link used for an IMD and the accompanying CMOS front end for the application space of neural recording in the brain of lab mice. The design process of the CMOS IC, along with thinning techniques, the nearfield inductive link, and the design of an external reading system will be discussed in detail. The various wireless power and data telemetry techniques applicable for IMDs and their strengths and weaknesses will also be described. Software techniques and implementation for real-time analysis of a high data rate communication system from the designed IMD will be covered. Finally, transceiver verification will be given for both power and data telemetry under various scenarios, with front end verification performed via controlled lab bench experiments using input sinusoidal wave forms

Signal-Processing-Driven Integrated Circuits for Energy Constrained Microsystems.

The exponential growth in IC technology has enabled low-cost and increasingly capable wireless sensor nodes which provide a promising way forward to realize the vision of a trillion connected sensors in the next decade. However there are still many design challenges ahead to make these sensor nodes small,low-cost,secure,reliable and energy-efficient to name a few. Since the wireless nodes are expected to operate on a limited energy source or in some cases on harvested energy, the energy consumption of each building block is of prime importance to prolong the life of a sensor node. It has been found that the radio communication when active has been one of the highest power consuming modules on a sensor node. Low-energy protocols, e.g. processing the raw sensor data on-node, are more energy efficient for some applications as compared to transmitting the raw data over a wireless channel to a cloud server. In this thesis we explore signal processing techniques to realize a low power radio solution for wireless communication. Two prototype chips have been designed and their performance has been evaluated. The first prototype chip exploits compressed sensing for Ultra-Wide-Band (UWB) communication. UWB signals typically require a high ADC sampling rate in the receiver which results in high power consumption. Compressed sensing is demonstrated to relax the ADC sampling rate to save power. The second prototype chip exploits the sensitivity vs. power trade-off in a radio receiver to achieve iso-performance at lower power consumption and the time-varying wireless channel characteristics are used to adapt the sampling frequency of the receiver based on the SNR/Link quality of the communication channel, saving power, while maintaining the desired system performance. It is envisioned that embedded machine learning will play a key role in the integration of sensory data with prior knowledge for distributed intelligent sensing which might enable reduced wireless network traffic to a cloud server. A Near-Threshold hardware accelerator for arbitrary Bayesian network was designed for clique-tree message passing algorithm used for probabilistic inference. The hardware accelerator was benchmarked by the mid-size ALARM Bayesian network with total energy consumption of 76nJ for 250µS execution time.PhDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/107130/1/oukhan_1.pd