L’objectif était de concevoir et réaliser des architectures alvéolaires performantes pour les récepteurs solaires volumétriques des futures centrales thermodynamiques. Trois stratégies différentes sont envisagées pour l’ébauche des préformes carbones ou céramiques : (i) la synthèse de matériaux biomorphiques issus de la découpe de balsa, (ii) l’élaboration de structures céramiques par projection de liant et (iii) la réplication de structures polymères réalisées par impression 3D, à l’aide d’une résine précurseur de carbone ou céramique. Dans tous les cas, les préformes crues sont converties par pyrolyse en C ou SiC et une étape d’infiltration/revêtement de SiC par CVD (Chemical Vapor Deposition) achève la fabrication des structures céramiques. Une étape intermédiaire de RCVD (Reactive CVD) a été mise en œuvre au cours de la première voie, afin de convertir la structure carbonée microporeuse en TiC. La composition, la microstructure et l’architecture poreuse des structures céramiques ont tout d’abord été caractérisées. Les caractéristiques des matériaux les plus pertinentes, compte tenu de l’application en tant qu’absorbeur solaire, ont ensuite été examinées. Les propriétés thermomécaniques et la résistance à l’oxydation ont ainsi été caractérisées en priorité. La perméabilité et les propriétés thermo-radiatives, qui sont également deux facteurs importants pour l’application, ont également été considérées. / The aim is to design and create efficient cellular architectures for volumetric solar receivers used in the future thermodynamic power plants. Three strategies are considered for the creation of ceramic or carbon preforms: (i) the synthesis of biomorphic materials resulting from the cutting of balsa, (ii) the elaboration of ceramic structures by binder jetting and (iii) the replication of polymer structures made by 3D printing, using a carbon or ceramic precursor resin. In all cases, the green preforms are converted by pyrolysis to C or SiC and an infiltration step / SiC coating by CVD (Chemical Vapor Deposition) completes the manufacture of ceramic structures. An intermediate stage of RCVD (Reactive CVD) was implemented during the first strategy, in order to convert the microporous carbonaceous structure into TiC. The composition, the microstructure and the porous architecture of the ceramic structures were first characterized. The characteristics of the most relevant materials, considering the application as a solar receiver, were then examined. The thermomechanical properties and the oxidation resistance have thus been characterized in priority. Permeability and thermo-radiative properties, which are also two important factors for application, were also considered.

Wireless spectrum is a limited resource that must be used efficiently. It is also a broadcast medium, hence, additional procedures are required to maintain communication over the wireless spectrum private. In this thesis, we investigate three key issues related to efficient use and privacy of wireless spectrum use. First, we propose GAVEL, a truthful short-term auction mechanism that enables efficient use of the wireless spectrum through the licensed shared access model. Second, we propose CPRecycle, an improved Orthogonal Frequency Division Multiplexing (OFDM) receiver that retrieves useful information from the cyclic prefix for interference mitigation thus improving spectral efficiency. Third and finally, we propose WiFi Glass, an attack vector on home WiFi networks to infer private information about home occupants. First we consider, spectrum auctions. Existing short-term spectrum auctions do not satisfy all the features required for a heterogeneous spectrum market. We discover that this is due to the underlying auction format, the sealed bid auction. We propose GAVEL, a truthful auction mechanism, that is based on the ascending bid auction format, that avoids the pitfalls of existing auction mechanisms that are based on the sealed bid auction format. Using extensive simulations we observe that GAVEL can achieve better performance than existing mechanisms. Second, we study the use of cyclic prefix in Orthogonal Frequency Division Multiplexing. The cyclic prefix does contain useful information in the presence of interference. We discover that while the signal of interest is redundant in the cyclic prefix, the interference component varies significantly. We use this insight to design CPRecycle, an improved OFDM receiver that is capable of using the information in the cyclic prefix to mitigate various types of interference. It improves spectral efficiency by decoding packets in the presence of interference. CPRecycle require changes to the OFDM receiver and can be deployed in most networks today. Finally, home WiFi networks are considered private when encryption is enabled using WPA2. However, experiments conducted in real homes, show that the wireless activity on the home network can be used to infer occupancy and activity states such as sleeping and watching television. With this insight, we propose WiFi Glass, an attack vector that can be used to infer occupancy and activity states (limited to three activity classes), using only the passively sniffed WiFi signal from the home environment. Evaluation with real data shows that in most of the cases, only about 15 minutes of sniffed WiFi signal is required to infer private information, highlighting the need for countermeasures.

Made available in DSpace on 2014-07-29T16:25:15Z (GMT). No. of bitstreams: 1 rosana araujo.pdf: 1178894 bytes, checksum: 9164fe2a0afb8cc84020730a28658e34 (MD5) Previous issue date: 2010-03-11 / This study aims the analysis of the productive process in music considering the optics of the receiver. This analysis focuses on the history of the occidental music guided by the aesthetic theory of the perception, its conclusions and projections in the musical field. It is the analysis of the relationship between the receiver and the formal space where the music takes place in the actual and metaphoric sense in the contingencies and circumstances that surround the act of surfacing. The objective is the search of an up to date vision about the musical reception beyond the simple sensorial perception. In the process, there is a discussion about the places of music production and reception, the concepts of perception, musical linguistics, and its ways of been learned. Also, there is a debate about the process of musical structure considering the perspective and aesthetical linked to the soundscape and acoustic. / Com foco na história da música ocidental e norteado pelas teorias da estética da recepção, suas inferências e projeções no campo musical, este estudo visa investigar o processo produtivo em música sob a ótica do receptor. Trata-se de uma análise da relação do receptor com os espaços formais de realização da música no sentido tanto concreto quanto metafórico nas contingências e circunstâncias que o cercam e conformam o ato da fruição. O objetivo é buscar uma visão atualizada da recepção musical que ultrapasse a questão da pura percepção sensorial. Discutem-se, portanto, ao longo da história da música ocidental, além dos lugares de produção e recepção da música, os conceitos de sentido, lingüisticidade musical e seus modos de apreensão, bem como os processos de estruturação musical numa perspectiva e estética vinculadas à acústica e à paisagem sonora.

Abstract The goal of this work was to develop a CMOS receiver for a time-of-flight (TOF) laser rangefinder utilizing sub-ns pulses produced by a laser diode operating in gain switching mode (~ 1 nJ transmitter energy). This thesis also discusses the optical detector components and their usability with sub-ns optical pulses in laser rangefinding and the effect of the laser driver electronics on the shape of the sub-ns laser output, and eventually on the timing walk error of the laser rangefinder. The thesis presents the design of an integrated receiver channel IC intended for use in the pulsed TOF rangefinder. This is realized in a low-cost and consumer electronics-friendly CMOS technology (0.18 μm) and is based on a linear receiver and leading edge time discrimination. The measured walk error of the receiver is ~ 500 ps (4.5 cm in distance) within a 1:21,000 dynamic range. The measured jitter of the leading edge, affecting the single-shot precision of the radar, was ~ 12 ps (1.6 mm in distance) at an SNR > 200. In addition, a pulsed TOF rangefinder using the receiver IC developed here was designed and used for demonstrating the possibility of measuring tiny vibrations in a distant non-cooperative target. The radar was used successfully to observe 10 Hz vibrations in a non-cooperative target with an amplitude of 1.5 mm (sub-mm precision after averaging) at a distance of ~ 2 m. One important result was the demonstration of a difference in walk error behaviour between MOSFET and avalanche BJT-based laser pulse transmitters. The practicability of an integrated CMOS AP detector in sub-ns laser rangefinding was also studied. / Tiivistelmä Työn tavoitteena oli kehittää CMOS-vastaanotin valon kulkuaikamittaukseen perustuvaan laseretäisyysmittariin, joka hyödyntää ”gain-switching”-tekniikalla toimivan laserdiodin (~ 1 nJ energia) tuottamia alle nanosekuntiluokan laserpulsseja. Väitöskirja tutkii myös valovastaanotinkomponenttien käyttökelpoisuutta alle nanosekuntiluokan laserpulsseja hyödyntävässä laseretäisyysmittauksessa. Työssä tutkitaan myös laserdiodilähettimen elektroniikan vaikutusta alle nanosekuntiluokan laserpulssien muotoon ja lopulta niiden vaikutusta systemaattiseen ajoitusvirheeseen laseretäisyysmittauksessa. Väitöskirja esittelee suunnitellun valopulssin kulkuaikamittaukseen perustuvaan laseretäisyysmittariin soveltuvan integroidun vastaanotinkanavan IC-piirin. Se on toteutettu halvalla, kulutuselektroniikkaan soveltuvalla CMOS tekniikalla (0,18 μm) ja se perustuu lineaariseen vastaanottimeen ja nousevan reunan ilmaisuun. Vastaanottimen mitattu systemaattinen ajoitusvirhe on ~ 500 ps (4,5 cm matkassa) 1:21 000 signaalivoimakkuuden vaihtelualueella. Vastaanottimesta mitattu laseretäisyysmittarin kertamittaustarkkuuteen vaikuttava nousevan reunan satunnainen ajoitusepävarmuus oli ~ 12 ps (1.6 mm matkassa) signaalikohinasuhteella > 200. Lisäksi tässä työssä toteutettiin kehitettyä vastaanotin-IC piiriä hyödyntävä valopulssin kulkuaikamittaukseen perustuva etäisyysmittari, jolla kyettiin havainnollistamaan mahdollisuutta mitata pientä tärinää kaukaisessa passiivisessa kohteessa. Tutkalla onnistuttiin havainnoimaan 1,5 mm vaihteluväliltään olevaa 10 Hz tärinä ~ 2 m etäisyydellä olevasta kohteesta. Väitöskirjan yksi tärkeä tulos oli havainnollistaa systemaattisessa ajoitusvirheessä havaittava ero MOSFET-transistoriin ja vyöry-BJT-transistoriin perustuvan laserpulssilähettimen välillä. Integroidun CMOS AP vastaanotinkomponentin käyttökelpoisuus alle nanosekuntiluokan laseretäisyysmittauksessa tutkittiin myös.

Ce travail s’intéresse aux transmissions ultralarge bande (ULB) dans les réseaux sans fils. La diversité spatiale est introduite par l’utilisation du système multiple-input multiple-output (MIMO) comme une technique efficace pour lutter contre l’évanouissement dû aux trajets multiples dans les communications sans fils. Mais, souvent l’intégration d’antennes multiples au niveau de l’émetteur ou du récepteur est coûteuse. Comme alternative, nous proposons d’utiliser la diversité coopérative qui garantit des gains de diversité spatiale en exploitant les techniques MIMO traditionnelles sans avoir besoin d’antennes multiples. L’objectif est d’introduire la diversité coopérative aux systèmes de transmission ULB. Nous considérons deux techniques d’accès multiple avec des schémas de modulation différents (time hopping pulse position modulation TH-PPM et direct sequence binary phase shift keying DSBPSK) avec le protocole de coopération decode-and-forward (DF). Nous utilisons le récepteur Rake afin d’exploiter la diversité de trajet multiple et analysons les statistiques de variable de décision à la sortie de ce récepteur. Nous présentons des résultats de simulation de la performance en termes de taux d’erreur binaire (TER) du système étudié sous différents canaux UWB compte tenu de la norme IEEE 802.15.4a. Ces résultats montrent que la coopération avec des relais améliore significativement les performances de transmission ULB, et que le gain de diversité augmente proportionnellement avec le nombre de relais. En présence d’IAM, la performance du système se dégrade de manière significative, mais l’avantage de la coopération est encore modérément efficace. La performance dans ce cas est limitée en termes de diversité achevée parce que le canal entre la source et le relais en présence d’IAM devient moins favorable. C’est pourquoi nous proposons d’utiliser la technique de sélection d’antenne au relais afin d’améliorer la fiabilité du canal source-relais. Cette solution permet d’améliorer la performance grâce au gain de la diversité d’antennes multiples disponibles au relais toute en n’utilisant qu’une seule chaîne radiofréquence (RF), qui conduit à une réduction des coûts et de la complexité. / This work focuses on the ultra wideband (UWB) transmission in wireless networks. Spatial diversity is introduced by the use of multiple-input multiple-output (MIMO) system as an effective technique to overcome multipath fading in wireless communications. But the integration of multiple antennas at the transmitter or receiver is often costly. As an alternative, we propose to use the cooperative diversity that provides spatial diversity gains by exploiting the traditional MIMO techniques without the need for multiple antennas. The objective is to introduce cooperative diversity to UWB transmission systems. We consider two multiple access techniques with different modulation schemes (time hopping pulse position modulation TH-PPM and direct sequence binary Phase Shift Keying DS-BPSK) with the cooperation protocol decode-and-forward (DF). We use the Rake receiver to exploit multipath diversity and analyze the decision variable statistics at the output of the receiver. We present simulation results of the BER performance of the proposed system under different UWB channel given the IEEE 802.15.4a standard. Our results show that the cooperation with the relay significantly improves the performance of UWB transmission, and that the diversity gain increases with the number of relays. In the presence of MAI, the overall system performance degrades significantly, but the benefit of cooperation is still moderately effective. The performance in this case is limited in terms of attainable diversity that the source-relay link becomes worse when MAI is present. That is why we propose to use antenna selection at the relay receiver in order to improve the reliability of the source-relay link. This solution is shown to improve the performance by exploiting the diversity of the available antennas at the relay, while using a single Radio Frequency (RF) chains. This leads to reduced cost and complexity.

This thesis investigates aspects of the ecology, morphology, bioacoustics, genetic relatedness, biogeography and taxonomy of cicadas in the Pauropsalta annulata Goding and Froggatt species complex, across their entire eastern Australian geographical distribution. These cicadas seem to emerge at the same sites annually, although the exact duration of their life cycle is not known. They are wary and mobile insects, with individuals generally taking flight at the first sign of disturbance, which makes them challenging to record, capture and observe. The males produce distinctive calling songs that have a consistent rhythmic structure, which is critically important for attracting females. In most cases, the songs are biphasic, with a penetrating introductory or "buzzing" component that apparently functions in mate attraction and a strongly structured cueing or "lilting" component for mate localisation. Initially Pauropsalta annulata was thought to comprise a single species with some degree of geographically structured variation in its calling song. Consequently, various "song types" had been recognised, but their precise relationship to one another had never been investigated. Therefore the structure of their calling songs were compared statistically across individuals of three song types, and this revealed four discrete clusters that were demonstrated to be independent of one another and consistent in their calling song structure. Plotting the geographical distributions of these cicadas revealed that each of the P. annulata song types is independently distributed geographically, with areas of overlap that are relatively small. Calling song structure is consistent for each song type across extensive geographical space and this structure holds even into areas of sympatry. One song type showed consistent differences from the others in male genitalia structure, and female ovipositor length differs significantly among three of the other song types. Each song type was found to be strongly associated with a small number of tree species and these associations are maintained into areas of sympatry. The spatial ecological and morphological comparisons in song structure, plant associations and morphology made in this study demonstrate that the P. annulata song types actually represent a complex of cryptic species. Two of the song types appear to intergrade in areas of sympatric overlap in terms of calling songs, plant associations and morphology, and thus represent subspecies as defined in population genetics terms. The components of the male calling song were then investigated to determine their specific functions and thus how they could delimit species boundaries. Significant differences were found in dominant song frequency between three of the four species, and may contribute to differential mate attraction. Both components of the song of each species have the same dominant frequency. Consistent differences were also evident, among species and subspecies, in the rhythmic structure of the "lilting" component of the male calling song. This component contains repeated phrases and each one of these provides a cue to which the conspecific female may respond. Her response is timed for the brief silent interval between the phrases. At this point the calling song becomes a duet, which enables the male to locate the female, as he actively searches for her on the surrounding branches at this stage. The calling song is discussed in terms of random mating within gene pools of these cicadas and in terms of its role as part of their broader fertilisation mechanism. A molecular analysis of the P. annulata species complex was performed to examine the phylogenetic relationships across 12 species and four subspecies defined in this study, and estimate divergence times within the group. Individual specimens were sampled widely across the geographical distributions of the species and subspecies where possible to account for genetic variation across space. DNA sequences from two loci were amplified: mitochondrial CO1 ("barcoding region") and a large intron from the dynamin nuclear gene. Separate phylogenies were reconstructed for each locus using maximum parsimony procedures and Bayesian posterior sampling with implementation of a relaxed molecular clock. The phylogenies from both genes provided strong support for the monophyly of the P. annulata species complex, and nine of the species were monophyletic based on the CO1 gene. The remaining three emerged non-monophyletic. Based on a clock calibration of 0.0165s/s/myr, the monophyletic clades represented by extant P. annulata species diverged about 4.5-8.0 million years ago. Those species that emerged non-monophyletic had shallower divergences, with the exception of one species, which exhibited haplotype diversity that conferred up to 13.2% sequence divergence between allopatric populations in CO1. Dynamin produced a broadly similar phylogenetic pattern to that of CO1, but the relationships among individuals across the species and subspecies that emerged non-monophyletic differed substantially. This lack of congruence between the two genomes, in combination with the dominance of internal haplotypes in both loci, indicates an overall pattern of deep coalescence rather than interspecific hybridization. Therefore the molecular data do not provide an alternative definition of species limits in the P. annulata species complex, despite some emerging non-monophyletic in this analysis. Sound interpretation of the phylogenetic pattern discovered here would not have been possible without the acoustic, ecological and geographical investigations on species limits that preceded this work. To determine what biological and climatic factors influence the present day distributions of these cicadas, the distributions of two of the most closely related species in the P. annulata species complex were compared with the distributions of the tree species with which each is mainly associated. Because a large part of their life cycle is subterranean, soil texture, pH, electrical conductivity and force required for surface penetration were compared across sites where each of the cicadas occur in sympatry and allopatry. Finally, the influence of temperature and rainfall variables were investigated by testing 'predicted distribution' models (formed using positive distribution records) against negative records for both sets of variables, individually and in combination. The results show that the extent of the distribution of the cicada species is substantially less than that of the associated tree species. The geographical distributions of one of the species may be influenced more by rainfall, or a combination of temperature and rainfall, whereas the other species appears to be more influenced by temperature alone. Both species tolerate soils with a wide range of pH levels, electrical conductivity and forces required for surface penetration. They both showed a strong association with soils that had a silt loam texture, with only few records from sandy soils. However, none of the soils sampled where the cicadas occurred were heavy clays, which suggests that the physical properties of such soils may provide an unsuitable environment for the nymphal stages of the life cycle of these particular cicadas. The resolution of species limits within the P. annulata species complex allowed the redescription of Pauropsalta annulata Goding and Froggatt sensu stricto and the description of 11 new species belonging to the P. annulata species group, all from eastern Australia. Two of these species comprise two subspecies each, also all new. New distribution records and calling song data are documented for the allied species, P. ayrensis Ewart, which is redescribed to include the characters newly recognised in the present study as significant taxonomically with respect to Pauropsalta cicadas. The treatment includes comprehensive descriptions of the morphology and calling songs of the species and subspecies, and separate descriptive keys are provided for both sets of characters. The new taxa comprise P. artatus sp. nov., P. corymbiae sp. nov., P. decorus sp. nov., P. graniticus sp. nov., P. inversus inversus subsp. nov., P. i. laboris subsp. nov., P. notialis notialis subsp. nov., P. notialis incitatus subsp. nov., P. simplex sp. nov., P. subtropicus sp. nov, P. torrensis sp. nov. and P. tremulus sp. nov. Areas of hybridization between P. n. notialis subsp. nov. and P. n. incitatus subsp. nov. are also documented, together with their calling songs and morphology, which justifies their subspecific status. The P. inversus subspecies are allopatric, but consistently differ in the duration between phrases of the calling song. Finally, the results and conclusions are amalgamated into a critical reassessment of what defines species limits and the most appropriate approaches to investigating species limits in sexual organisms. Some historical discussions are revisited, such as the question of the reality of species and how species are perceived under the premises of neoDarwinism. The realism of species demands that species limits are most realistically defined in terms of their fertilisation mechanism, for this delimits the gene pool and thus the distribution of adaptations (the calling song of cicadas, for example).

Avec l'arrivée des systèmes radio mobiles de troisième et de quatrième génération, les standards de communications ont tendance à occuper plus de bande pour pouvoir assurer des services de voix, de données et de multimédia. En parallèle, le terminal mobile doit être reconfigurable pour couvrir à la fois le service cellulaire et la connectivité de données. Dans ce contexte, la tendance est d'intégrer les fonctions radio et bandes de base sur le même substrat en utilisant la technologie CMOS afin de réduire la surface, le coût de fabrication et la consommation des terminaux sans fils. Récemment, de nouvelles architectures de réception radio dites " échantillonnées " sont apparues (TexasInstruments, STMicroelectronics, UCLA). Dans ce cas, l'échantillonnage est fait directement sur le signal RF et la majorité du traitement de signal se fait en temps-discret par des capacités commutées. L'évolution de la technologie CMOS et la miniaturisation des transistors rendent la conception analogique de plus en plus difficile (capacités parasites, bruit, linéarité, etc.). De nouveaux effets parasites apparaissent comme la fuite de grille qui inquiète désormais les technologues et les concepteurs de circuits. D'un autre côté, des contraintes de dynamique surgissent avec la diminution des tensions d'alimentation et le bruit des circuits numériques de plus en plus denses augmente considérablement. Le but de ce travail de thèse est de répondre à la question de la portabilité de la solution échantillonnée, en étudiant l'impact des différents effets parasites cités précédemment sur les performances radio de la solution. Ainsi, les critères de portabilité qui sont considérés sont la reconfigurabilité, l'immunité aux effets parasites, l'adaptation à la baisse des tensions d'alimentation, la surface, la consommation et la facilité de conception. Ce travail de thèse a été basé sur des études théoriques et sur des simulations d'une solution échantillonnée de réception radio. Afin d'affronter réellement les problématiques de portabilité, un portage d'une chaîne de réception échantillonnée Wi-Fi/WiMAX de CMOS 65nm à 45nm a été réalisé. Les résultats de mesures obtenus sur ce circuit donnent une grande confiance vis-à-vis des performances radio de la solution échantillonnée et constituent un premier élément de réponse concret à la question de portabilité étudiée.

One of the main challenges posed by 4G wireless communication systems is achieving flexible, programmable multi-standard radio transceivers with maximum hardware share amongst different standards at a minimum power consumption. Evaluating the feasibility and performance of different multi-standard/multi-band radio solutions at an early stage, i.e. system level, is key for succeeding in surmounting this challenge. This entails for- mulation of the transceiver budget for several RF architectures and frequency plans with different degrees of hardware sharing. This task is complicated by the fact that transceiver blocks can have different implementations that lead to different performances. The tools that are available for use at present have only analysis capabilities or address only one standard and/or receiver architecture at a time.In the belief that a new approach to this problem is necessary, the work that has led to this thesis proposes a novel methodology that automates the design-space explo- ration of integrated multi-standard wireless radio receivers. This methodology has been implemented in a multi-standard RF Transceiver Architecture Comparison Tool, TACT. TACT helps surmounting many of the challenges faced by RF system designers targeting multi-standard/multi-band radio receivers.The goal of the algorithms TACT is built upon is to find a multi-standard receiver frequency plan and budget that meets or exceeds the specifications of the addressed wire- less standards while keeping the requirements of each of the receiver blocks as relaxed as possible. TACT offers RF engineers a deep insight into the receiver behavior at a very early stage of the design flow. It models the impact of critical circuit non-idealities using a high level of abstraction. This reduces the number of design iterations and, thus, the time-to-market of the solution. The reuse of already available intellectual property (IP) blocks is also considered in TACT, what can result in a significant cost reduction of the receiver implementation. A combination of a behavioural-based cooperative multi-agent optimization and deterministic techniques is proposed.The capabilities of the proposed techniques and developed tool are illustrated through case studies addressing different design challenges the design of multi-standard receivers present.The last part of this thesis is devoted to one of the key blocks of any communica- tions receiver: the analog-to-digital converter. This work focuses on modeling and design methodologies for continuous-time ΔΣ modulators. A method to evaluate the stability margin of continuous-time ΔΣ modulators as a function of the timing uncertainty effects is proposed. / QC 20100907 / RaMSiS

The objective of this dissertation is to develop key components of a CMOS heterodyne millimeter-wave receiver front end. Robust designs are necessary to overcome PVT variations as well as modeling inaccuracies, while with minimum power consumption overhead to facilitate low-power radio for portable applications. Heterodyne receiver topology is adopted because of its robust performances at millimeter-wave frequencies. Device models for both passive and active devices are developed and used in the circuit designs in this dissertation. Two low-noise amplifiers (LNAs) are developed in this dissertation. The first LNA features a proposed temperature-compensation biasing technique, which confines the gain variation within 5 dB for temperature variation from -5 to 85 Celsius degree. The measured gain and NF are 21 and 6.5 dB, respectively, for 49-mW power dissipation. The second LNA reveals a design technique to tolerate a low-accuracy model at millimeter-wave frequencies. Both LNAs provide full coverage of the FCC 60-GHz band (57-64 GHz). For the frequency generation circuits, both the IF QVCO and mm-wave VCO are investigated. The inherent bimodal oscillation of QVCOs is analyzed and, for the first time, a systematic measurement technique is proposed to intentionally control the oscillation mode. This technique is further utilized to extend the tuning range of the QVCO, which possesses dual tuning curves without penalty on phase noise. The measurement results of a 13-GHz QVCO in 90-nm CMOS reveals a 21.4% tuning range for continuously tuning from 11.7 to 14.5 GHz. The measured phase noise is -108 dBc/Hz at 1 MHz offset with a core power consumption of 10.8 mW. A millimeter-wave VCO is designed and fabricated in 65-nm CMOS. The VCO is fully characterized under voltage stress to examine the hot-carrier injection effects affecting the performance of a millimeter-wave VCO. The 41.6-47.4 GHz VCO is further integrated into a millimeter-wave down converter. The power-hungry buffer amplifiers are neglected by proper floor planning. Conversion loss of 1.4 dB is obtained with total power consumption of 72.5 mW. Lastly, a power management system consisting of low-dropout (LDO) regulators is designed and integrated in a 90-nm CMOS millimeter-wave transceiver to provide stable and low-noise supply voltages. Voltage variation issues are alleviated by the LDOs.

In this Master's thesis, a direct-conversion receiver front-end has been designed in a 0.18um CMOS technology. Direct-conversion receivers (DCR) have obvious advantages over the heterodyne counterpart. Since the intermediate frequency (IF) is zero, the problem of image is circumvented. As a result, no front-end image reject filter is required and the channel selection requires only a low-pass filter, which makes it easy to integrate directly on chip. However, the DCR also suffers from several drawbacks such as extreme sensitivity to DC offsets, 1/f noise, local oscillator (LO) leakage/radiation, front-end nonlinearity and I/Q mismatch. This implies very high demands on the DCR front-end. The front-end comprises a low-noise amplifier (LNA) and a mixer. Different LNA and mixer architectures has been studied and from the mentioned inherited problems with direct conversion, one proposal for a solution is a differential source degenerated LNA and a differential harmonic mixer, which has been designed and simulated. The LNA has a gain of 12dB, a noise figure of 3.6dB and provides a return loss better than -15dB. The overall noise figure of the signal path is 8dB and the overall IIP3 and IIP2 is -12dBm and 31dBm, respectively.