Thesis (M.S.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-01

<p>This thesis focuses on the design and evaluation of the meander-line antenna geometry. One standard meander-line antenna and other two non-standard meander antennas have been studied. These printed antennas are discussed with the goal of identifying which is suitable for use in a miniaturized wireless transceiver design and which is able to provide the better performance using minimal Printed Circuit Board (PCB) space. In a word, the main objective is to characterize tradeoffs and identify which antenna provides the best compromise among volume, bandwidth and efficiency.</p><p>The performance of each antenna is evaluated based on return loss, operational bandwidth, and radiation pattern characteristics. During our measurement, return loss is measured by reading the S11-port reflection coefficient on Vector Network Analyzer (VNA). This coefficient can be used to characterize how well the antenna is able to be efficiently fed. Operational bandwidth is measured as the frequency range over which the antenna keeps the value of Voltage Standing Wave Ratio (VSWR) or equivalently has -10dB return loss. Ansoft High Frequency Structure Simulator (HFSS) is used to simulate expected characteristics which are resonant frequency, bandwidth, VSWR, and radiation pattern. HFSS is used to provide a good guide for the antenna design before the actual prototype is manufactured. Simulated results are compared with results of measurement to point out the differences and help demonstrate the practical effects on antenna performance. Radiation pattern are measured to illustrate the effects of antenna miniaturization. All the above measurements are done in the anechoic chamber.</p>

<p>The objective of this thesis work was to implement all the hardware and software necessary to simulate the functionality of a Vector Network Analyzer (VNA). With equipment that is already available, and is common in a measurement station, the most common functions of a VNA were implemented, using an Vector Signal Generator, that provide the signal for testing, and a Vector Signal Analyzer, to make all the amplitude and phase measurements. With these instruments and the appropriate software that control them, the basic functionality of a Vector Network Analyzer can be achieved with a reasonable accuracy. With this system, we can reduce costs, avoiding the need of a real VNA and take advantage off instruments that are already available in a laboratory. A Complete measurement system of all four scattering parameters is proposed at the end of the report for future implementation. With this implementation all the different S-parameter measurements were made with an acceptable accuracy that can be comparable to a commercial VNA.</p>

The objective of this thesis work was to implement all the hardware and software necessary to simulate the functionality of a Vector Network Analyzer (VNA). With equipment that is already available, and is common in a measurement station, the most common functions of a VNA were implemented, using an Vector Signal Generator, that provide the signal for testing, and a Vector Signal Analyzer, to make all the amplitude and phase measurements. With these instruments and the appropriate software that control them, the basic functionality of a Vector Network Analyzer can be achieved with a reasonable accuracy. With this system, we can reduce costs, avoiding the need of a real VNA and take advantage off instruments that are already available in a laboratory. A Complete measurement system of all four scattering parameters is proposed at the end of the report for future implementation. With this implementation all the different S-parameter measurements were made with an acceptable accuracy that can be comparable to a commercial VNA.

This thesis focuses on the design and evaluation of the meander-line antenna geometry. One standard meander-line antenna and other two non-standard meander antennas have been studied. These printed antennas are discussed with the goal of identifying which is suitable for use in a miniaturized wireless transceiver design and which is able to provide the better performance using minimal Printed Circuit Board (PCB) space. In a word, the main objective is to characterize tradeoffs and identify which antenna provides the best compromise among volume, bandwidth and efficiency. The performance of each antenna is evaluated based on return loss, operational bandwidth, and radiation pattern characteristics. During our measurement, return loss is measured by reading the S11-port reflection coefficient on Vector Network Analyzer (VNA). This coefficient can be used to characterize how well the antenna is able to be efficiently fed. Operational bandwidth is measured as the frequency range over which the antenna keeps the value of Voltage Standing Wave Ratio (VSWR) or equivalently has -10dB return loss. Ansoft High Frequency Structure Simulator (HFSS) is used to simulate expected characteristics which are resonant frequency, bandwidth, VSWR, and radiation pattern. HFSS is used to provide a good guide for the antenna design before the actual prototype is manufactured. Simulated results are compared with results of measurement to point out the differences and help demonstrate the practical effects on antenna performance. Radiation pattern are measured to illustrate the effects of antenna miniaturization. All the above measurements are done in the anechoic chamber.

Dans l’aéronautique et plus précisément dans les avions tout électrique, l’objectif visé est de réduire les masses et volumes des composants. Pour cela, les actionneurs électriques remplacent progressivement les actionneurs hydrauliques et mécaniques. Ces actionneurs électriques ont besoin d’être commandés ; le projet THOR (projet européen dans lequel s’inscrit cette thèse) vise entre autres à développer un étage de commande permettant de piloter des interrupteurs de puissance. Les interrupteurs étant situés à proximité directe de l’étage driver et les tensions de sorties pouvant atteindre 3 kV, une isolation galvanique est obligatoire. Anciennement, les optocoupleurs étaient utilisés pour assurer l’isolation galvanique dans les étages de commande. Cependant, afin de pouvoir utiliser ces composants dans un environnement thermique contraignant et assurer une meilleure intégration, les opto-coupleurs ne sont plus adaptés et sont remplacés par des transformateurs. Dans ce contexte, s’inscrivent les travaux de cette thèse où l’objectif principal est de développer, réaliser et caractériser des transformateurs planaires intégrables répondant au cahier des charges THOR. Dans un premier temps, un état de l’art sur les différentes technologies de fabrication de transformateurs planaires est établi avant de choisir la technologie et les matériaux utilisés dans ces composants. Dans un deuxième temps, on s’intéresse au choix et au dimensionnement du transformateur. Deux structures répondant au cahier des charges THOR ont été retenues et dimensionnées à l’aide d’un logiciel de simulation (HFSS) : une structure entrelacée et une structure ‘face to face’. Ces deux structures ont été réalisées et caractérisées à l’aide d’un LCRmètre en basse fréquence et d’un Analyseur Vectoriel de Réseaux (VNA) en haute fréquence. Pour les deux structures, la caractérisation a permis de vérifier les valeurs des inductances magnétisantes supérieures à 1 μH souhaitées par le projet THOR et des facteurs de couplages supérieurs à 0,9 déterminées par simulation. D’autres paramètres importants du cahier des charges ont été également extraits à savoir la capacité interbobinage où des capacités inférieures à quelques pF ont été obtenues et des résistances d’enroulement inférieures à 10 Ω ont été relevées / In aeronautics and more specifically in an all-electric aircraft, the main objective is to reduce the mass and volume of the components. For this, the electric actuators gradually replace hydraulic and mechanical actuators. These electric actuators need to be commanded; THOR project (European project supporting this thesis) aims to develop a control stage to command the power switches. The switches are located in the direct vicinity of the driver stage with an output voltage that can reach up to 3 kV hence the need for a galvanic isolation. Formerly, the opto-couplers were used to provide galvanic isolation in the control stages. However, in order to use these components in thermal constraining environment and ensure better integration, opto-couplers are no longer appropriate and are replaced by transformers. In this context, the main objective of this thesis is to develop, realize and characterize integrated planar transformers that meet the THOR specifications. At first a state of art on the different manufacturing technologies of planar transformers is established before choosing the technology and the materials used in the fabrication of our planar transformers. In a second step, we are interested in the choice and size of the transformer structure. Two structures that met the THOR specifications were selected and resized using a simulation software (HFSS). Finally, these two structures were realized and characterized using an RLC-meter at low frequency and a Vector Network Analyzer (VNA) at high frequency. For both structures, the characterization allowed to verified the magnetizing inductance greater than 1 μH desired by the THOR project and a coupling factor greater than 0,9 obtained par simulations. Other important parameters were also extracted namely the inter-winding capacity where less than few pF wasobtained and the windings resistance has been identified less than 10 Ω

Le travail présenté dans ce manuscrit a pour objet l’étude et le développement d’un banc de caractérisation généraliste appliqué à l’extraction du modèle comportemental d’amplificateur TPM-NIM (Two-Path Memory Nonlinear Integral). Ce modèle qui dispose d’une des architectures les plus abouties au laboratoire XLIM requiert une instrumentation microonde haut de gamme, très onéreuse, hors de portée de la majorité des concepteurs pour sa mise en œuvre expérimentale. L’objectif est donc de proposer des principes de mesure originaux permettant d’identifier le modèle TPM-NIM avec une instrumentation standard. Dans ces travaux, deux bancs sont présentés : tout d’abord, un banc de caractérisation développé autour d’une instrumentation de pointe disposant des meilleures propriétés pour extraire le modèle. Puis, un banc construit autour d’une instrumentation standard mais incluant des méthodes de traitement et de mesure novatrices. Ces deux bancs ont été utilisés avec plusieurs véhicules de tests et il ressort que le second permet de diminuer le bruit des mesures de phase tout en réduisant le coût total des équipements. Enfin, une dernière partie est consacrée à la comparaison du modèle TPM-NIM avec deux modèles comportementaux classiques mettant en avant sa polyvalence. / The work presented in this manuscript is devoted to the study and development of a general characterization bench applied to the extraction of the TPM-NIM (Two-Path Memory Nonlinear Integral) amplifier behavioral model. This model, has one of the most advanced architectures at the XLIM laboratory. It requires a high-end microwave instrumentation, overpriced and beyond reach for most of the designers for its experimental implementation. The aim is to propose some original measurements principles allowing the TPM-NIM model’s identification with a standard instrumentation. Two benches are presented in these works : firstly, a characterization bench, developed using a high performance instrumentation with the best properties to extract the model. Then, a bench, built with a standard instrumentation but through innovative processing and measurement methods. These two benches have been used with several test vehicles and it appears that the second one decreases the noise of phase measurements while reducing the equipment’s total cost. Finally, a last part is dedicated to the comparison of the TPM-NIM model with two classic behavioral models by emphasizing its versatility.

A greater understanding of precessional dynamics in magnetic systems is central to several emerging technologies. This thesis presents the design, construction and development of a Vector Network Analyser based Ferromagnetic Resonance measurement instrument (VNA-FMR), and its application in characterising dynamic material properties in hybrid anisotropy [CoPd]8-NiFe films, produced by remote plasma sputtering. Potential applications for hybrid films include Spin Torque Oscillators (STOs) or Vortex Oscillators (VO) for use as microwave emitters in, for example in Microwave Assisted Magnetic Recording (MAMR). The VNA-FMR system was first used to measure thin films of NiFe (permalloy) which allowed its capabilities to be quantified and compared to systems reported in the literature. The instrument demonstrated the capability of measuring permalloy films down to a thickness of 3 nm and was used to measure resonance and damping behaviour which agreed well with theory. The results obtained forMs were in agreement with measurement using Vibrating Sample Magnetometry. The effect of interlayer exchange on FMR was explored in hybrid films using a sample series with varying Pd spacer layer thickness, t, [Co/Pd]-Pd(t)-NiFe. As Pd spacer thickness increased, a transition was observed from near complete coupling with a single resonance mode to separate acoustic and optical branches of resonance. As spacing was further increased, the branches converged towards the resonances of the individual component layers of the hybrid films. The results suggest exchange coupling has a range of less than 2 nm, and is completely extinguished at 5 nm, in agreement with previous measurements. However, a change in damping behaviour was observed between 10 and 20 nm spacer thickness, independent of field orientation.

An Improved Short-Open-Load-Reciprocal (SOLR) Vector Network Analyzer (VNA) calibration is developed and validated. Through the use of a more complex load model the usable frequency range of the SOLR calibration algorithm is expanded. Comparisons are made between this new calibration and existing calibration techniques that are known to be accurate at high frequencies. The Anritsu 37xxx Lightning series 65GHz VNA is used as the principle measurement tool for calibration comparison and verification. This work is built off of previous work done at USF in which it is shown that the Short-Open-Load-Thru (SOLT) calibrations accuracy improves through the implementation of more complex load and thru models. One of the most significant advantages of the SOLR calibration algorithm is that it does not require an ideal well behaved thru standard. This is extremely useful in multiport probing environments where it is often necessary for speed and space conservation purposes to use loopback thrus or other non-ideal transmission structures during calibration. Multiport test equipment and measurement techniques are highlighted and discussed. A general n-port expansion of a two-port calibration algorithm is presented and used to adapt the improved two-port SOLR algorithm to a four-port calibration. In doing so a theoretical development that addresses error model treatment, and switch term corrections is presented that includes an improved set of the redundancy equations that enable the multiport SOLR algorithm. The algorithm uses a four-port SOL calibration at each port and then determines the remaining error terms by measuring a minimal set of reciprocal passive standards. The four-port SOLR algorithm developed was illustrated through the use of a four-port test set that consists of a two-port VNA input multiplexed to four-ports through an RF switch array. Verification of the four-port SOLR calibration is made by comparing it to available four-port calibration techniques using available on-wafer test structures. As another promising advance of the work the possibility of using of a multiport reciprocal standard is shown to have potential for reducing the number of standard connections needed to accomplish multiport SOLR calibration. Differential measurements are facilitated through mixed-mode calculations of single ended S-parameter measurements made with the four-port SOLR calibrations improved with this work.

Les TBH SiGe sont parmi les composants les plus rapides et sont utilisés pour les applications millimétriques. Des systèmes fonctionnent à 820GHz avec ces composants ont été déjà mis en œuvre. Afin de concevoir des circuits fonctionnant à ces fréquences très élevées, une analyse détaillée du comportement intrinsèque doit être effectuée. L’objectif principal de cette thèse est la caractérisation de la partie intrinsèque de ces composants. Une bonne précision de mesure dans la gamme de fréquences ondes millimétriques représente un vrai challenge, puisque les grandeurs intrinsèques du dispositifs ont beaucoup plus faibles que les données brutes de mesure auxquelles est associée la partie extrinsèque du composant. Afin de corriger la partie extrinsèque, des techniques de de-embedding spécifiques sont mises au point pour obtenir ces caractéristiques intrinsèques réelles. De plus, une technique de calibration directement sur la puce, sans utiliser de calkit, a été élaborée. Ceci permet de s’affranchir des effets de couplage entre la surface du standard de calibrage et les pointes de test hyperfréquences. L’ensemble a été validé par des simulations de type électromagnétique. / SiGe HBTs have proven their capability to support large bandwidth and high data ratesfor high-speed communication systems. Systems operating at 820GHz with these componentshave already been implemented. To design circuits operating at high frequencies, adetailed analysis of the intrinsic behavior should be performed. The main objective of thisthesis is the characterization of the intrinsic part of these components. Good accuracy inthe millimeter wave frequency range represents a real challenge, since the intrinsic deviceparameters are much lower than the raw data measurement that is associated with theextrinsic part of the component. However, existing on-wafer de-embedding techniquesare known to be inadequate to remove completely the parasitic effects and to get thereal intrinsic characteristics. In addition, an on-wafer calibration technique has beendeveloped. This overcomes the effects of coupling between the surface of the standard calibrationand RF probe tips. The set has been validated by an electromagnetic simulation.