4 research outputs found

    Crystal-Less RF Communication Integrated Circuits for Wireless Sensor Networks.

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    The evolution of computing devices has changed daily life significantly over the past decades, and it is still advancing towards pervasive and ubiquitous networks. At each step, the volume shrinks by 2-3 orders of magnitude while the functionality and computing power remains constant or increases. Wireless sensor networks (WSN) are perceived as the next big step of computing technology for a variety of applications, including environmental sensing, health monitoring, un-obtrusive surveillance and invisible labeling. With thin-film micro-battery technology and CMOS scaling, we can now envision complete sensor nodes with cubic-mm form factors. As node volume reduces, external components like a crystal frequency reference, which does not scale with frequency or process, becomes one of the bottlenecks of realizing cubic-mm WSN node devices. This dissertation covers several aspects of the energy and integration challenges associated with cubic-mm WSN nodes without crystal references. Several new compact and low-power RF circuits for the synchronization and communication of WSN nodes are proposed and discussed. A 60GHz antenna-referenced frequency-locked loop (FLL) using an on-chip patch antenna as both the radiator and the frequency reference has been demonstrated for RF synchronization. The FLL, targeting communication of non-coherent energy detection systems, provides adequate frequency accuracy without crystal references. A 10GHz ultra-wideband (UWB) crystal-less transmitter with an on-chip monopole antenna has also been demonstrated. It operates over the supply voltage range of a micro-battery; generate tunable pulse durations and center frequencies, and lives on an on-chip local decoupling capacitor only. A 1MHz temperature-compensated relaxation oscillator is also proposed in the dissertation for baseband data synchronization. With the modified RC network of the conventional relaxation oscillator, the transfer function of the network has a transmission zero, introducing an additional degree-of-freedom for temperature compensation design. Finally, a 60GHz transmit/receive (T/R) switch-less antenna front-end using an on-chip patch antenna is presented, which has an in-band isolation inherited from the standing wave pattern without implementing a T/R switch. The research projects have explored the circuit design techniques and system integration for cubic-mm energy-constrained devices, achieving both long lifetimes and small volumes for WSN applications.PhDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/99763/1/kkhuang_1.pd

    Radio-frequency integrated-circuit design for CMOS single-chip UWB systems

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    Low cost, a high-integrated capability, and low-power consumption are the basic requirements for ultra wide band (UWB) system design in order for the system to be adopted in various commercial electronic devices in the near future. Thus, the highly integrated transceiver is trended to be manufactured by companies using the latest silicon based complimentary metal-oxide-silicon (CMOS) processes. In this dissertation, several new structural designs are proposed, which provide solutions for some crucial RF blocks in CMOS for UWB for commercial applications. In this dissertation, there is a discussion of the development, as well as an illustration, of a fully-integrated ultra-broadband transmit/receive (T/R) switch which uses nMOS transistors with deep n-well in a standard 0.18-μm CMOS process. The new CMOS T/R switch exploits patterned-ground-shield on-chip inductors together with MOSFET’s parasitic capacitances in order to synthesize artificial transmission lines which result in low insertion loss over an extremely wide bandwidth. Within DC-10 GHz, 10-18 GHz, and 18-20 GHz, the developed CMOS T/R switch exhibits insertion loss of less than 0.7, 1.0 and 2.5 dB and isolation between 32-60 dB, 25-32 dB, and 25-27 dB, respectively. The measured 1-dB power compression point and input third-order intercept point reach as high as 26.2 and 41 dBm, respectively. Further, there is a discussion and demonstration of a tunable Carrier-based Time-gated UWB transmitter in this dissertation which uses a broadband multiplier, a novel fully integrated single pole single throw (SPST) switch designed by the CMOS process, where a tunable instantaneous bandwidth from 500 MHz to 4 GHz is exhibited by adjusting the width of the base band impulses in time domain. The SPST switch utilizes the synthetic transmission line concept and multiple reflections technique in order to realize a flat insertion loss less than 1.5 dB from 3.1 GHz to 10.6 GHz and an extremely high isolation of more than 45 dB within this frequency range. A fully integrated complementary LC voltage control oscillator (VCO), designed with a tunable buffer, operates from 4.6 GHz to 5.9 GHz. The measurement results demonstrate that the integrated VCO has a very low phase noise of –117 dBc/ Hz at 1 MHz offset. The fully integrated VCO achieves a very high figure of merit (FOM) of 183.5 using standard CMOS process while consuming 4 mA DC current

    Architectures multi-bandes en mode impulsionnel et circuits pour des applications nomades très haut débit autour de 60GHz

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    Avec la croissance actuelle du marché des applications de transfert de données multimédia à très haut débit, les bandes de fréquences autour de 60 GHz sont une nouvelle alternative promettant des performances intéressantes en terme de débits mais soulèvent des défis techniques et technologiques au niveau des architectures et circuits. C'est dans ce cadre que s'inscrit cette thèse, qui propose une approche multi bande impulsionnelle MBOOK avec un récepteur à détection d'énergie, et qui analyse plus spécifiquement les verrous au niveau de l'émetteur. L'étude du canal de propagation à 60 GHz, basée sur les modèles de canaux du standard IEEE 802.15.3c, a permis de démontrer la potentialité de cette architecture et permet d'atteindre des débits de 2 Gbps à 2metres dans un environnement de type résidentiel. Le dimensionnement de l'architecture ainsi que des performances des principaux blocs ont conduit à plusieurs possibilités pour l'architecture de l'émetteur MBOOK à 60 GHz. Les critères ont été d'assurer un compromis performances, consommation. Une étude approfondie sur l'étude des imperfections de certains blocs critiques et l'impact sur l'impulsion transmise, et donc sur les performances du système ont été établies. Le banc de filtres, nécessaire à l'émission et à la réception, représente l'un des verrous, et nous proposons une solution de filtrage à base de lignes couplées. L'étude des solutions de génération d'impulsions, des étages de commutation, et des étages d'amplification de l'émetteur sont détaillées et discutées dans les deux derniers chapitresWith the current increasing market request concerning high speed data rates applications, the 60 GHz frequency bands seems to be one of the new promising alternatives for high data rate wireless communications. In this context, the development of new systems operating at these frequencies becomes a very attractive research subject. This study focuses on nomadic systems offering high data and reconfigurable rates, low complexity, low power consumption for short communications. One of the important tasks in the millimetre wave architecture design is to consider the channel propagation characteristics simultaneously with the technological performance of integrated circuits and antennas. This requires a co-design of the entire system. Therefore, we begun by studying the characteristics of the channel propagation channel at 60GHz according to the IEEE 802.15.3c and IEEE 802.11.ad models. This PHD thesis proposes a new transceiver architecture based on multi-band impulse mode, with On Off Keying modulation schema and non coherent receiver. This architecture is dedicated to nomadic systems offering high data and reconfigurable rates, low complexity, low power consumption for short communications. Analysis and performances for the proposed architecture are presented. More than 2 Gbps at 2 m are obtained. The imperfections of some critical blocks and their impact on the transmitted pulses were analysed and thus the performance of the system has been established. The potentiality of microstrip band pass filter bank presenting a constant relative bandwidth and reasonable insertion losses is presented in this study. The study of pulse generation solutions, switchers, amplification stages and antennas are detailed and discussed in the last two chaptersconstant relative bandwidth and reasonable insertion losses is presented in this study.The study of pulse generation solutions, switchers, amplification stages and antennas are detailed and discussed in the last two chapters.PARIS-EST-Université (770839901) / SudocSudocFranceF

    Beamforming ultra-wideband transmitter

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    Master'sMASTER OF ENGINEERIN
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