In a communication system, the group delay variation (GDV) causes the distortion of signal and the degradation of symbol error rate. Usually, the compensation of group delay (GD) utilizing positive group delay (PGD) results in further propagation delay. Therefore, this research studies the negative group delay (NGD) behavior of metamaterial. Through analyzing the effects on GD caused by poles and zeros of circuit, the group delay circuit capable of switching between NGD and PGD is presented. Further, adjustable negative group delay circuits (NGDCs) are designed based on the concept of poles and zero. The NGD generated by NGDC is used to achieve the equalization of GD and recover the distorted signal in time domain. Additionally, owing to the limited frequency band of communication, a filter with high selectivity is required to utilize the available bandwidth. The character of left-handed metamaterial is applied to the design of filter for reducing the size and cost of traditional microstrip line filters with high selectivity. Under the balanced condition, composite right/left-handed (CRLH) transmission line behaves right- and left- handed characteristics in different frequency bands. Thus, a coplanar waveguide (CPW) filter with high selectivity, size reduction and low cost is presented utilizing such a CRLH structure.

Left handed metamaterials are one of the most populer topic attracting attentions of scientists nowadays. Metamaterials are engineered materials which can possess inordinary properties when compared with common materials existing in nature. The main structure investigated in this thesis is fishnet metamaterial which is a left handed metamaterial. Firstly some left handed metamaterials and their properties are surveyed. A retrieval procedure in order to obtain permittivity, permeability and refractive index of any periodic material was summarized. Left handedness of fishnet structure was investigated and proven numerically. Effects of change in polarization of an incoming wave to symmetric and asymmetric fishnet structure were searched. A parametric analysis of fishnet structure was done. Phase advance in a three layered fishnet structure was investigated and compared with phase advance in an ordinary material. Fishnet wedge structure was surveyed and negative refraction and negative phase advance in this structure are shown. Finally, some types of disorderness of fishnet structure, then its effects on transmission results and retrieval results are demonstrated. In order to obtain transmission and reflection through a material, CST Microwave Studio&reg / was used. A code following a numerical procedure in order to retrieve constitutive parameters of a periodic structure which was written in Matlab&reg / was used in this thesis.

This dissertation describes the approach taken in measuring two neutrino double beta decay of Cd-116 to the ground state of Sn-116 and in searching for the effective Majorana neutrino mass by placing a lower limit on the half-life for neutrinoless double beta decay of Cd-116 using the powerful technique of a combined tracking chamber and calorimeter with the NEMO-3 detector. The description of the detector, its natural background contamination, and the tools used to perform the analysis are discussed. The single electron channel was used to identify source foil contamination from [beta]-emitters and the electron-gamma channel was used to confirm the previous measurements of Tl-208 and Bi-214 contaminations in the source foil. Using these backgrounds, the two neutrino double beta decay half-life of Cd-116 was measured for the single states dominance hypothesis and the higher states dominance hypothesis. The final data set was defined to be data from Phrase One and Phase Two for the medium and low activity regions. Using 1471 days of data, the values of the half-life for the single data dominance hypothesis and the higher states dominance hypothesis were found. / text

Dans la perspective d’un contrôle ultime de la lumière, les arrivées récentes des cristaux photoniques et des métamatériaux constituent des avancées majeures. Ces matériaux nano-structurés présentant des propriétés optiques inédites nous ouvrent tout un champ de possibilités encore inexploré. En particulier, des milieux d’indice effectif négatif sont rendus concevables. L’objectif de cette thèse est d’étudier d’un point de vue électromagnétique, à l’aide d’outils analytiques et numériques, le comportement de la lumière dans ces structures exotiques. Nous nous penchons sur les boucles de lumières, qui sont des modes localisés d’une structure multi-couches, émergeant du couplage contra-directionnel entre deux guides distincts. Une analyse physique est proposée et un modèle basé sur la théorie des modes couplés est développé. Cela nous permet de décrire avec précision l’excitation d’une boucle de lumière par une source lumineuse, et d’envisager des applications pour la mise en forme de faisceau. Dans une seconde partie, nous étudions des cristaux photoniques unidimensionnels formés par une alternance de milieux d’indices positif et négatif. Lorsque l’indice moyen est nul, une bande interdite aux propriétés nouvelles apparait. Nous montrons que le caractère dispersif des milieux transforme des pics étroits de transmission en larges bandes. Pour caractériser la propagation d’un faisceau dans un tel cristal, nous développons et validons alors un modèle qui nous permet de démontrer le potentiel en matière de mise en forme de faisceau (auto-collimation, focalisation). / In the perspective of an ultimate control of light, the recent arrivals of photonic crystals and metamaterials are major advances. These nano-structured materials with unusual optical properties are opening a whole range of possibilities still unexplored. In particular, negative index media have became conceivable. The aim of this thesis is to study, with an electromagnetic point of view, the behavior of light in these exotic structures, using analytical and numerical tools. We study the light wheels, which are localized modes of a multi-layer structure, emerging from the contra-directional coupling between two separate waveguides. A physical analysis is proposed and a model, based on the coupled mode theory, is developed. This allows us to accurately describe the excitation of a light wheel by a source, and to consider applications for beam shaping. In a second part, we study one-dimensional photonic crystals combining positive and negative index layers whose the average index is equal to zero. A band gap, called zero-n gap, appears and presents new properties that we detail. Index dispersion is shown to broaden the resonant frequencies creating then a conduction band lying inside the zero-n gap. Self-collimation and focusing effects are in addition demonstrated in zero-average index crystals supporting defect modes. This beam shaping is explained in the framework of a beam propagation model by introducing an harmonic average index parameter.

In the thesis presented, three novel uni-planar left handed transmission lines based on Complementary Split Ring Resonators (CSRR) and Complementary Spiral Resonator (CSR) metamaterial particles are proposed for the first time and successfully applied for the performance enhancement of conventional coupled line filters and the design of a full scan leaky wave antenna. Based on the implementation of Complementary Split Ring Resonators (CSRR) a fully planar Composite Right left handed transmission line (CRLH-TL) plus a Dual Composite Right Left Handed transmission line (D-CRLH-TL) are proposed, designed and studied. The CRLH transmission line is realized loading a microstrip host line with CSRR metamaterial particles and capacitive gaps on the conductor strip of the line, while the D-CRLH transmission line is built bridging the capacitive gaps between the CSRR's with inductive connections to induce dual propagation properties in the structure. A further performance enhancement is achieved by a second proposal based on the implementation of Complementary Spiral Resonators (CSRs). The studies applied to the structure reveal that conditions for D-CRLH propagation are created in a transmission line composed only by CSR metamaterial resonant particles as the result of the unique electromagnetic properties acquired by the CSRs etched on the conductor line of a microstrip waveguide. The CSRR/CSR based D-CRLH transmission lines proposed are applied in the design of two enhanced coupled line filters. The implementation is possible for the first time in this work as result of the highly versatile layout features of the left handed transmission lines proposed which among other important geometrical features, allows couplings in both sides of the structure. Enhanced filtering features are reached by the metamaterial based coupled line filters proposed in terms of selectivity and size reduction in comparison with conventional coupled line filters. In the case of the CSRR loaded metamaterial coupled line filter a size reduction of 49% is achieved compared with a filter of similar performance. A further enhancement is reached by the second coupled filter proposed based on CSR metamaterial resonant particles. The CSR coupled filter proposed reach a roll off rate improvement of 8 dB/GHz and size reduction of 43% in comparison with a conventional coupled line filter of the same order. When this is compared against a conventional coupled line filter of similar performance but higher order, a remarkable size reduction of 77% is achieved by the proposed CSR coupled line filter. Finally, the CSR loaded D-CRLH transmission line is applied in the design of a fully planar leaky wave antenna. Using the CSR structures etched on the conductor line of a microstrip as part of the radiation mechanism altogether with the D-CRLH propagation features of the structure. A full scan radiation pattern is created with backward, forward and broadside radiation as result of the left handed propagation band, right handed propagation band and the balanced transition between them. Two leaky wave antennas are designed to operate at the centre frequencies of 12.5GHz and 6.0GHz. In order to corroborate the performance the CSR D-CRLH leaky wave antenna operating at 6.0GHz is fabricated and measured showing a scanning range of 30 deg with a maximum gain of 13.2 dBi.

Portable, handheld, and wearable devices are an integrate part of everyday life, yet there is no well-established text inputmethod for devices with very small screens. Speech to text has been a quick fix, but entails privacy concerns and can beobtrusive. Chord keyboards bring various advantages for application in a mobile environment, as they require fewer keys andcan thus be small and portable. The aim of this work is to suggest an alternative to the QWERTY keyboard, suitable for textentry on devices of all sizes, shapes and mobility requirements. A one hand operational chord keyboard was developed andevaluated in a small user study with regard to its social acceptability. Learnability showed to be a concern that discouragesuse, while social aspects did not seem to be an issue.

Paul Wittgenstein (1887-1961) made significant contributions to the piano literature for the left hand through numerous commissioned works as well as his own transcriptions. In the transcriptions, Wittgenstein preserved the texture of two-hand music, aiming for the simulation of the original works. This requires special techniques in the performance by the left hand alone. This dissertation investigations technical means and performance problems associated with the transcriptions as well as Wittgenstein's own recordings of selections from his works. Chapter 1 serves as an introduction, providing a historical overview of the role of the left hand in two-hand piano literature. Chapter 2 gives biological information on Paul Wittgenstein and discusses the commissioned works. Chapter 3 investigates special techniques in the transcriptions, in the areas of arpeggios, widespread chords, fingering, pedaling, and others. Chapter 4 discusses Wittgensteins's performance style based on his recordings. Chapter 5 presents a conclusion pointing to the benefits of performing left-hand music in two-hand piano playing.

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In this work, waveguides with simultaneous negative dielectric permittivity and magnetic permeability, otherwise known as left-handed waveguides, are investigated. An approach of formulating and solving an eigenvalue problem with finite element method resulting in the dispersion relation of the waveguides is adopted in the analysis. Detailed methodology of one-dimensional scalar and two-dimensional vector finite element formulation for the analysis of grounded slab and arbitrary shaped waveguides is presented. Based on the analysis, for waveguides with conventional media, excellent agreement of results is observed between the finite element approach and the traditional approach. The method is then applied to analyze left-handed waveguides and anomalous dispersion of modes is found. The discontinuity structure of a left-handed waveguide sandwiched between two conventional dielectric slab waveguides is analyzed using mode matching technique and the results are discussed based on the inherent nature of the materials. The scattering characteristics of a parallel plate waveguide partially filled with left-handed and conventional media are also analyzed using finite element method with eigenfunction expansion technique.

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