Dissertations / Theses: 'Resonators'

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Thorvaldsson, Thor. "Design and analysis of surface acoustic wave resonators and resonator filters /." [S.l.] : [s.n.], 1988. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=8471.

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Pourkamali, Siavash. "High frequency capacitive single crystal silicon resonators and coupled resonator systems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/26563.

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Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2007.
Committee Chair: Ayazi, Farrokh; Committee Member: Allen, Mark; Committee Member: Brand, Oliver; Committee Member: Degertekin, Levent; Committee Member: Papapolymerou, John. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Nelson, John. "Novel optical resonators." Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3130/.

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Optical resonators – two mirrors facing each other, separated by a distance – are a very well studied technology. However, even such a well understood technology can sometimes present surprises. The first part of this thesis investigates the surprising properties of some canonical optical resonators. The basic properties of resonators are introduced. The imaging properties of stable and unstable resonators are examined. The second part of this thesis examines the potential use of grating- coupled cavities in gravitational wave detectors and describes an exper- iment carried out on a 10 m prototype of such a cavity.

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Hendricks, Jason Mark. "Holographic laser resonators." Thesis, University of Southampton, 2002. https://eprints.soton.ac.uk/15485/.

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The work presented within this thesis details the development and characterisation of a CW solid-state adaptive resonator that uses phase-conjugation to actively correct for phase distortions present within the resonator loop. It is shown that the phase-conjugate of a given beam can be produced by the process of degenerate four-wave mixing inside a gain medium. In this scheme two mutually coherent beams overlap within a population inverted region of a laser amplifier and the subsequent interference pattern between them spatially hole burns a grating into the gain. The diffraction efficiency of such gain-gratings is studied both theoretically and experimentally and it is shown that, due to the stored inversion, CW phase-conjugate reflectivities of greater than 100 can be achieved in Nd:YVO4. Using this gain four-wave mixing scheme an adaptive resonator is built that is capable of oscillating with a phase-conjugate mode. The ability of the volume gain-grating to encode and react dynamically to phase distortions present within the resonator loop ensures that the phaseconjugate output beam from the resonator always remains a faithful reproduction of the beam used to seed the resonator. The interactions occurring within the resonator are modelled and a resonator capable of producing an 11.6 W near-diffraction limited output is demonstrated. The powerscaling capabilities of such lasers is then considered and it is shown that the output power can be increased whilst maintaining phase-conjugate oscillation. It is shown that a phase-conjugate output of 6 W can be scaled to 11.7 W with the addition of a power amplifier placed into the existing setup.

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Chen, Wei-Yen. "Benzocyclobutene microring resonators." College Park, Md.: University of Maryland, 2007. http://hdl.handle.net/1903/7695.

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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.
Thesis research directed by: Dept. Electrical and Computer Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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Calton, Matthew Franklin. "Modeling of Acoustic Resonators and Resonator Systems for Use in Passive Noise Control." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/9261.

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Acoustic resonators, such as the Helmholtz and quarter-wave resonator, can be used to attenuate unwanted noise in an enclosed space. Classical formulations can be used to approximate resonator performance for a given resonator configuration, but may lack sufficient accuracy for some applications. This research aims to improve the analytical characterization of resonators to provide better correlation to experimental results. Using higher-order approximations and proper end corrections, more accuracy can be obtained in calculating the impedance and resonance frequency of a single resonator, which will then carry over into the overall configuration of the model. The impedance of a system of resonators in parallel is also considered, where the effects of acoustic coupling can be observed. Resonators with complex, non-ideal geometries are explored for applications where space is limited. The effects of tapers and toroidal curves are considered using impedance translation methods. These theoretical predictions are found to compare favorably with empirical data. Coupling between an enclosure and resonator system is explored experimentally. The effects of resonator placement, damping, and relative cavity and enclosure volume are considered. These data are used to design and test a resonator system with 10 dB of attenuation over a bandwidth of 10 Hz.

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Ho, Gavin Kar-Fai. "Design and characterization of silicon micromechanical resonators." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/29634.

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Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.
Committee Member: David R. Hertling; Committee Member: Farrokh Ayazi; Committee Member: Gary S. May; Committee Member: Oliver Brand; Committee Member: Paul A. Kohl. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Wei, Lei. "Fiber resonators and lasers." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ53524.pdf.

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Othman, M. B. "Silicon-based micromechanical resonators." Thesis, University of Southampton, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374856.

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Popa, Laura C. "Gallium nitride MEMS resonators." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99296.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 187-206).
As a wide band-gap semiconductor, with large breakdown fields and saturation velocities, Gallium Nitride (GaN) has been increasingly used in high-power, high-frequency electronics and monolithic microwave integrated circuits (MMICs). At the same time, GaN also has excellent electromechanical properties, such as high acoustic velocities and low elastic losses. Together with a strong piezoelectric coupling, these qualities make GaN ideal for RF MEMS resonators. Hence, GaN technology offers a platform for the seamless integration of low-loss, piezoelectric RF MEMS resonators with high power, high frequency electronics. Monolithic integration of MEMS resonators with ICs would lead to reduced parasitics and matching constraints, enabling high-purity clocks and frequency-selective filters for signal processing and high-frequency wireless communications. This thesis highlights the physics and resonator design considerations that must be taken into account in a monolithically integrated solution. We then show devices that achieve the highest frequency-quality factor product in GaN resonators to date (1.56 x 1013). We also highlight several unique transduction mechanisms enabled by this technology, such as the ability to use the 2D electron gas (2DEG) channel of High Electron Mobility Transistors (HEMTs) as an electrode for transduction. This enables a unique out-of-line switching capability which allowed us to demonstrate the first DC switchable solid-state piezoelectric resonator. Finally, we discuss the benefits of using active HEMT sensing of the mechanical signal when scaling to GHz frequencies, which enabled the highest frequency lithographically defined resonance reported to date in GaN (3.5 GHz). These demonstrated features sh
by Laura C. Popa.
Ph. D.

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Cherenack, K. H. (Kunigunde Hadelinde). "Modelling of layered cylindrical dielectric resonators with reference to whispering gallery mode resonators." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52942.

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Thesis (MScEng)--University of Stellenbosch, 2002.
ENGLISH ABSTRACT: Keywords: Dielectric Resonators, Radial Mode Matching, Whispering Gallery Modes The aim of this investigation was to develop accurate modelling techniques to determine the resonant frequencies of dielectric resonators. These resonators could be simple dielectric posts, rings or combinations of these two. To do this, a radial mode matching technique was implemented and applied to a post resonator, a ring resonator and finally a combination of the two. The resulting method was used to develop a model of a high-Q whispering gallery mode resonator consisting of a post and a ring resonator combination with an spurious free region region.
AFRIKAANSE OPSOMMING: Sleutelwoorde Dielektriese Resoneerders, Radiale Modale-Pas Tegniek, 'Whispering Gallery' Modus Die doel van hierdie navorsing was om 'n akkurate tegniek te ontwikkelom die resonante frekwensie van 'n dielektriese resoneerder vas te stel. Hierdie resoneerders kon eenvoudige resoneerders, ring resoneerders of kombinasies van die twee wees. 'n Radiale Modale-Pas tegniek is vir hierdie doel geïmplementeer en is op 'n eenvoudige resoneerder, 'n ring-resoneerder en kombinasies van die twee toegepas. Hierdie tegniek is dan gebruik om 'n hoë-Q resoneerder te ontwerp wat gebruik maak van 'n 'whispering gallery' modus. In hierdie geval is die resoneerder 'n kombinasie van 'n pil en 'n ring-resoneerder.

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Samarao, Ashwin Kumar. "Compensation and trimming for silicon micromechanical resonators and resonator arrays for timing and spectral processing." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39543.

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This dissertation reports very novel solutions for the trimming and compensation of various parameters of silicon micromechanical resonators and resonator-arrays. Post-fabrication trimming of resonance frequency to a target value is facilitated by diffusing in a deposited thin metal layer into a Joule-heated silicon resonator. Up to ~400 kHz of trimming-up and trimming-down in a 100 MHz Silicon Bulk Acoustic Resonators (SiBARs) are demonstrated via gold and aluminum diffusion respectively. The dependence of the trimming range on the duration of Joule heating and value of current passed are presented and the possibility of extending the trimming range up to ~4 MHz is demonstrated. Passive temperature compensation techniques are developed to drastically reduce the temperature coefficient of frequency (TCF) of silicon resonators. The dependence of TCF on the charge carriers in silicon are extensively studied and exploited for the very first time to achieve temperature compensation. A charge surplus via degenerate doping using boron and aluminum is shown to reduce a starting TCF of -30 ppm/°C to -1.5 ppm/°C while a charge depletion effected by creating multiple pn-junctions reduces the TCF to -3 ppm/°C. Further, shear acoustic waves in silicon microresonators have also been identified to effect a TCF reduction and have been excited in a concave SiBAR (or CBAR) to exhibit a TCF that is 15 ppm/°C lesser than that of a conventional rectangular SiBAR. The study on quality factor (Q) sensitivity to the various crystallographic axis of transduction in silicon resonators show that the non-repeatability of Q across various fabrication batches are due to the minor angular misalignment of ≤ 0.5° during the photolithography processes. Preferred axes of transduction for minimal misalignment sensitivity are identified and novel low-loss resonator-array type performances are also reported from a single resonator while transduced along certain specific crystallographic axes. Details are presented on an unprecedented new technique to create and fill charge traps on the silicon resonator which allows the operation of the capacitive SiBARs without the application of any polarization voltages (Vp) for the first time, making them very attractive candidates for ultra-low-power oscillator and sensor applications. Finally, a fabrication process that integrates both the capacitive and piezoelectric actuation/sensing schemes in microresonators is developed and is shown to compensate for the parasitics in capacitive silicon resonators while maintaining their high-Q.

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Laschitsch, Alexander Thomas. "Dynamical measurements with quartz resonators." [S.l.] : [s.n.], 2000. http://ArchiMeD.uni-mainz.de/pub/2000/0021/diss.pdf.

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Ciressan, Nicoleta-Diana. "Nanogap MEM resonators on SOI /." [S.l.] : [s.n.], 2009. http://library.epfl.ch/theses/?nr=4484.

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El-Sabbagh, Adel. "Gas-filled axisymmetric acoustic resonators." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/3177.

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Thesis (Ph. D.) -- University of Maryland, College Park, 2005.
Thesis research directed by: Mechanical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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Humad, Shweta. "Piezo-on-Silicon Microelectromechanical Resonators." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5069.

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This thesis reports on the use of sputter-deposited zinc-oxide as a transduction mechanism to actuate and sense single crystal silicon (SCS) microelectromechanical (MEMS) resonators. Low frequency prototypes of piezo-on-silicon resonators with operating frequencies in the range of hundreds of kHz were implemented using micromechanical single crystal silicon clamped-clamped beam resonators. The resonators reported here extend the frequency of this technology into very high frequency (VHF range) by using in-plane length extensional bulk resonant modes. This thesis outlines the design, implementation and characterization of high-frequency single crystal silicon (SCS) block resonators with piezoelectric electromechanical transducers. The resonators are fabricated on 4m thick SOI substrates and use sputtered ZnO as the piezo material. The centrally supported block resonators operate in their first and higher order length extensional bulk modes with high quality factor (Q). Measurement results are in good agreement with the developed ANSYS simulations.

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Sivapurapu, Abhishek. "Piezoelectrically-Transduced Silicon Micromechanical Resonators." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7478.

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This thesis reports on the design and fabrication of micro-electro-mechanical (MEM) resonators on silicon that are piezoelectrically-transduced for operation in the very high frequency (VHF) range. These devices have a block-type or beam-type design, and are designed to resonate in their in-plane and out-of-plane bulk extensional modes. Two piezoelectric materials were taken into consideration, zinc-oxide (ZnO) and lead-zirconate-titanate (PZT). The resonators are fabricated on silicon-on-insulator (SOI) wafers and the metal/piezo/metal stack of layers forming the device is built and patterned on the device layer silicon via photolithography techniques, RF sputtering (for the piezo-layer) and electron-beam evaporation (for the metal layers). The designing aspect involved ANSYS simulations of the mode-shapes and estimation of frequencies, and these have correlated well with experimental results. Devices with RF sputtered ZnO were successfully fabricated and tested to give high quality factors at reasonably high frequencies. A gold ground plane was implemented to reduce the feed-through level and increase the signal-to-noise ratio. Extensive characterization of PZT was also done as a replacement for ZnO, as the former material has a much higher piezoelectric coefficient (~20X that of ZnO) and can therefore extend the operation of these MEM resonators into the UHF range. Although the basic design of the device remains the same, incorporation of PZT complicates the process flow considerably with respect to the chemistry now involved with the patterning of different layers. The frequency response for ZnO-based resonators as well as all the characterization data for PZT has been reported.

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Heckl, Maria Anna. "Heat sources in acoustic resonators." Thesis, University of Cambridge, 1985. https://www.repository.cam.ac.uk/handle/1810/250863.

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Lee, Jimmy. "Vibration studies on TRIUMF resonators." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26305.

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The Cyclotron Division of Triumf, Canada's national meson facility, initiated a study to design replacement RF resonators which when in place would improve the quality of the particle beam produced by the cyclotron. A hot-arm, a major structure of a resonator, experiences thermal-related structural deformation and flow-induced structural vibration which reduces the spatial stability of the particle beam. The scope of this report encompasses studies on the hot-arm vibration to determine the desirable characteristics for a replacement hot-arm design which would reduce hot-arm vibration. The improved beam stability will be beneficial for the types of experiments conducted now at Triumf. In the future, it will be beneficial for the proposed Kaon Factory; Triumf has requested funds to construct a kaon producing factory encircling the existing cyclotron. The vibrating hot-arm is modelled analytically to be a transversely vibrating cantilever beam. Investigations are carried out on the following areas: 1. the nature of the vibration excitation forces originating from the coolant water flowing in the hot-arm; 2. the effectiveness of adding a lumped mass, a rotational stiffener and damping, to the cantilever beam model, in reducing beam vibration; 3. the minimum-weight design of a lightly damped variable-cross-section sandwich cantilever beam, subjected to a unit harmonic point force at the free tip, with constraint on the tip amplitude; 4. the minimum-weight design of a lightly damped variable-cross-section sandwich cantilever beam, subjected to a random rain force with white noise power spectral density over the beam span, with constraint on the mean square tip deflection; 5. the optimal design of a dynamic vibration absorber to attenuate the hot-arm vibration and 6. the influence of the shape of the coolant-flow channel on the magnification of the flow-induced excitation in a hot-arm. A possible design for the replacement hot-arm is discussed.
Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate

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Dietrich, Christof Peter. "Cavity effects in polygonal resonators." Doctoral thesis, Universitätsbibliothek Leipzig, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-104393.

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In der vorliegenden Arbeit werden ZnO-Mikronadeln bezüglich ihrer Anwendbarkeit als Mikroresonatoren untersucht. Dabei stehen Kavitätsmoden im Fokus der Untersuchungen, die sich nur senkrecht zur Nadelachse ausbreiten, sprich innerhalb der hexagonalen Nadelquerschnittsfläche. Folglich wird der Einfluss der Gestalt der Querschnittsfläche auf Resonatoreigenschaften wie Propagation, Form, Direktionalität und Qualität der Kavitätsmoden sowohl theoretisch simuliert als auch experimentell nachgewiesen. Die dabei beobachteten hohen Qualitätsfaktoren von Flüstergalerie-Moden ermöglichen es darüberhinaus, Wechselwirkungseffekte zwischen Kavität und Mode zu beobachten. Der erste Teil der Arbeit beschäftigt sich mit der regulären, polygonalen Resonatorform und deren Einfluss auf die Dimensionalität von Kavitätsmoden sowie deren mögliche Wechselwirkung mit dem elektronischen System des Resonators. Beispielhaft wird ein hexagonaler Resonator zur Veranschaulichung gewählt, wie er durch ZnO-Mikronadeln gegeben ist, undmittels Finite-Difference-Time-Domain (FDTD)-Simulationen sowie winkelaufgelöster Photolumineszenz (PL)-Spektroskopie untersucht. Die aufgenommenen PL-Spektren können unter Zuhilfenahme photonischer Dispersionskurven von ein- und zwei-dimensionalen Kavitätsmoden reproduziert werden. Basierend auf diesen Ergebnissen wird der Einfluß der Resonatorecken auf die Lichtauskopplung diskutiert und mittels winkelaufgelöster, anregungsabhängiger und temperaturabhängier PL-Spektroskopie nachgewiesen. Desweiteren wird auf die Wechselwirkung zwischen dem Resonator und den Kavitätsmoden eingegangen, imSpeziellen auf die starke Kopplung zwischen Flüstergalerie-Moden und freien Exzitonen imResonatormaterial. Bereits erschienende Publikationen zu diesemThema werden präsentiert und kritisch hinterfragt. Dabei wird ein Leitfaden aufgestellt, der eine Evaluierung möglicher Polaritonen-Phänomene ermöglicht. Um Wechselwirkungen dieser Art auch in den hier untersuchtenMikronadeln nachzuweisen, werden Hochanregungs-PL-Messungen durchgeführt. Dabei werden Messungen in der Mitte der Nadel sowie in der Nähe ihrer Ecken getätigt, um spezielle Polaritonen-Propagationseffekte beobachten zu können. Im zweiten Teil der Arbeit wird der Einfluß von irregulären und inhomogenen Resonatorformen auf die Bildung von Flüstergalerie-Moden diskutiert. Dafür werden elongierte Teile der Nadeln, die durch laterale Auswüchse entstehen, winkelaufgelöst bezüglich einer gerichteten Auskopplung von Kavitätsmoden vermessen und verzerrte Mikronadeln, wie sie beim Biegen entstehen, bezüglich der entstehenden Deformationseffekte und deren Einfluss auf die Kavitätsmoden mittels hochaufgelöster Mikro-PL untersucht. Die experimentellen Ergebnisse zu irregulären Resonatoren können durch FDTD-Simulationen bestätigt werden. Desweiteren wurden Mikronadel- und Nanonadel-Quantengraben-Heterostrukturen hergestellt und deren Lumineszenzeigenschaften diskutiert. Dabei wird speziell auf die Homogenität der Quantengrabenemission eingegangen und Strategien zur Realisierung einer starken Kopplung zwischen Flüstergalerie-Moden und Quantengraben-Exzitonen aufgestellt. Diese Strategien werden experimentell umgesetzt und deren Ergebnisse anhand von Kathodolumineszenzmessungen vorgestellt.

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Dusatko, Tomas A. "Silicon carbide RF-MEM resonators." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100250.

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A low-temperature (<300°C) method to fabricate electrostatically actuated microelectromechanical (MEM) clamped-clamped beam resonators has been developed. It utilizes an amorphous silicon carbide (SiC) structural layer and a thin polyimide spacer. The resonator beam is constructed by DC sputtering a tri-layer composite of low-stress SiC and aluminum over the thin polyimide sacrificial layer, and is then released using a microwave O 2 plasma etch. Deposition parameters have been optimized to yield low-stress films (<50MPa), in order to minimize the chance of stress-induced buckling or fracture in both the SiC and aluminum. Characterization of the deposited SiC was performed using several different techniques including scanning electron microscopy, EDX and XRD.
Several different clamped-clamped beam resonator designs were successfully fabricated and tested using a custom built vacuum system, with measured frequencies ranging from 5MHz to 25MHz. A novel thermal tuning method is also demonstrated, using integrated heaters directly on the resonant structure to exploit the temperature dependence of the Young's modulus and thermally induced stresses.

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Veerasubramanian, Venkatakrishnan. "Applications of sidewalled grating resonators." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114418.

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Recent developments in cutting edge fabrication techniques have led to research focused oncombining multiple optical and electronic functionalities, and to the integration of variousactive and passive components onto a single die. Integrated optical devices using waveguidesare being developed to replace traditional free space propagating devices utilizinglenses and mirrors. Silicon based photonic integrated circuits (PIC) are being investigatedfor intra-board and board-to-board optical interconnection in high speed computing, andas transceivers in high speed optical communications. One of the major aspects in PICresearch is the miniaturization of passive devices performing various functions such as opticalfiltering, multiplexing, demultiplexing, wavelength routing, and optical isolation. Inthis thesis, we study and demonstrate the feasibility of using sidewalled gratings for opticalfiltering, wherein optical feedback is obtained by the interaction of the guided mode withperiodic index modulations realized vertically on the waveguide walls.A novel design based on a horizontal evanescent coupling scheme in sidewalled gratingresonators for realizing low reflection filters that reduces the need for isolators or circulatorsis presented and demonstrated. We utilize the narrowband filter response of aquarter wave shifted cavity to obtain transmission filters with 110 GHz bandwidth. A coupledcavity scheme wherein multiple identical cavities are coupled back-to-back to obtaintop-hat like filter response (with 50 dB/nm roll-off) is also demonstrated. Multichannelwavelength filters designed using sampled grating distributed Bragg reflectors (SG-DBR)is introduced, and a novel dual apodization method for realizing comb resonances withhigh side mode suppression ratio (SMSR) is discussed in detail. The apodized comb filtersare shown to exhibit channel spacing, bandwidth, and SMSRs within prescribed standardlimits. We also present through numerical simulations, the feasibility of employing sidewalledgratings as wavelength selective cavities in hybrid III–V silicon lasers, and in tunableevanescent lasers. Results on dimensional engineering of the cavity to obtain the requiredlasing wavelength and confinement factors are presented. All the devices being presentedin this thesis were fabricated using an inductively coupled plasma based dry etch processon a silicon-on-insulator (SOI) wafer, where the pattern transfer was done using e-beamlithography (EBL).
Les développements récents dans les techniques de fabrication de pointe ont conduit à des recherches axées sur la combinaison de multiples fonctionnalités optiques et électroniques et à l'intégration de différents composants actifs et passifs sur une matrice unique. Des dispositifs optiques intégrés à l'aide de guides d'ondes sont en cours de développement pour remplacer les traditionnels dispositifs de propagation en espace libre qui utilisent des lentilles et des miroirs. Des circuits photoniques intégrés (PIC) à base de silicium sont à l'étude pour les connexions optiques à l'intérieur d'un circuit ou entre des circuits pour le traitement de donnée à haute vitesse et comme émetteurs-récepteurs dans les communications optiques à haut débit. L'un des aspects majeurs de la recherche sur les PIC est la miniaturisation des dispositifs passifs qui exercent des fonctions diverses telles que le filtrage optique, le multiplexage, le démultiplexage, le routage des longueurs d'onde et l'isolement optique. Dans cette thèse, nous étudions et démontrons la faisabilité d'utiliser des réseaux sur les parois d'un guide d'ondes pour le filtrage optique. Dans ces dispositifs, la rétroaction optique est obtenue par l'interaction du mode de propagation avec des modulations périodiques de l'index de réfraction réalisées à la verticale sur les parois du guide d'ondes.Une conception originale reposant sur un système de couplage évanescent horizontaldans les résonateurs à réseaux est présentée et démontrée pour la réalisation de filtres à faible réflexion qui réduit la nécessité d'utiliser des isolateurs ou des circulateurs. Nous utilisons la réponse à bande étroite d'une cavité quart d'onde décalée afin d'obtenir des filtres de transmission de 110 GHz de bande passante. Un système dans lequel plusieurs cavités identiques sont couplées en série pour obtenir un filtre avec une réponse chapeau haut de forme (avec 50 dB/nm d'affaiblissement) est également démontré. Des filtres de longueurs d'onde à multiple canaux conçus à l'aide de réflecteurs de Bragg à multiples réseaux (SGDBR) sont présentés et une nouvelle méthode d'apodisation double pour la réalisation de filtre en peigne avec une grande suppression des modes secondaires (SMSR) est discutée en détails. Les filtres en peigne apodisés présentés démontrent des espacements de canaux, des bandes passantes et des SMSRs dans les limites standard. Nous présentons également, pardes simulations numériques, la possibilité d'employer des réseaux sur les parois d'un guide d'ondes comme cavités sélectives de longueurs d'onde pour les lasers hybrides III–V sur silicium et les lasers évanescents accordables. Les résultats sur la détermination des dimensions de la cavité pour obtenir la longueur d'onde d'émission et les facteurs de confinement requis sont présentés. Tous les dispositifs présentés dans cette thèse ont été fabriqués en utilisant un procédé de gravure sèche à plasma couplé par induction sur un substrat de silicium sur isolant (SOI), où le transfert de motif a été fait en utilisant la lithographie par faisceau d'électrons (EBL).

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Albaho, Tareq Ibrahim Jasim. "Theory of empty optical resonators." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429594.

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Shackleton, Christian John. "Resonators for slab-waveguide lasers." Thesis, Heriot-Watt University, 1993. http://hdl.handle.net/10399/1387.

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Melnick, Joshua Robert. "Aluminum Nitride Countour Mode Resonators." Thesis, Rochester Institute of Technology, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1591270.

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Resonators are a major component in RF electronic products. They are used in a host of ways to filter radio signals. Modern and Future RF communications have placed high demands on the industry; requiring low power usage, wide array of applications and resistance to noise.

In this thesis, a discussion of the motivation for RF MEMS filters and basic theory is given with an explanation of the concepts of Q factor, piezoelectricity, acoustics theory, the major types of resonators (SAW, BAW, CMR or LAMB), apodization theory and techniques as well as design, simulation of CMR and BAW devices, testing and process development of aluminum nitride by RF reactive sputtering at RIT.

Finite element analysis was performed on a number of factors of aluminum nitride contour mode resonators (CMR) from piezoelectric film thickness, to electrode pitch, electrode thickness and electrode configuration; to understand the effects. First order and second order vibration modes were seen including symmetric S₀, S₁ and antisymmetric A₀, A₁ resonant modes in the pizeoacoustic devices and higher. A series of time dependent video simulations of SAW, BAW and LAMB wave resonators were also performed, perhaps the first of their kind.

The RF reactive sputtering deposition for aluminum nitride was developed at RIT by a fractional factorial experiment with the factors being RF power, nitrogen to argon flow rate ratios, changing the distance of the wafer to the platen from 5 to 4 cm, use of a aluminum, molybdenum or virgin silicon seed layer and chamber pressure. In nearly all cases it was found that an RF power of 1000W is the most important factor contributing to the ⟨002⟩ orientation. The decreasing of the target distance may inhibit a reaction mechanisms in the plasma resulting in a more amorphous deposition. It may be due to the increase in temperature resulting from the higher RF power that promotes the growth of ⟨002⟩ oriented aluminum nitride. A molybdenum seed layer tends to have a stronger ⟨002⟩ peak relative to aluminum and a chamber pressure of 3mT was found to exhibit a deposition that most favors the ⟨002⟩ oriented aluminum nitride.

It was found that molybdenum is not consumed in a wet etch of KOH. Molybdenum is oxidized during photo resist ashing. The Contact Vias were necessarily over retched in order to ensure complete removal of Al-N over the Bottom Electrode.

C-V measurements were done on the aluminum nitride to determine its quality, the measured extensional piezoelectric coefficient d₃₃ is -0.000108716 nm/V, which is -0.108716 pm/V lower than 8pm/V typically reported. The lower piezo electric coefficient measured as compared with typical values, may be due to low film density a result of the high power used in the RF reactive sputtering that was used to heat the platen to a high enough temperature to promote the?002?oriented growth of AlN.

A series of iterations were designed and S11 frequency response measured. The electrode overlap from 25 to 50 to 75μm, it does not appear to have an effect on the resonant frequency, but does increase the amplitude of the response at that die's given frequency. Increasing the anchor width from 5μm to 10μm to 20μm lowers the relative amplitude of the response therefore lowering the Q of the resonator. It may be that the increasingly wide anchor, increases the mechanical resistances within the device and thereby lowers the Q factor of the resonator. Increasing the number of electrodes increases the relative amplitude of the response. Increasing pitch from 5μm to 6μm seems to have a small effect on the resonant frequency of the devices, shifting them from 4.57 to 4.59 GHz. A quality factor was measured, with an anchor width of 5μm, pitch of 5μm, 24 electrodes and an electrode overlap of 75μm had a measured Q value of 98.8.

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Patel, Trupti. "Nanomechanical resonators for SQUID readout." Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10043534/.

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Nano-electromechanical systems (NEMS) are an important new class of device, with a growing range of applications, from tests of quantum mechanics through to nanoscale metrology and a vast number of different sensors. Cryogenic operation is also possible, and at low temperatures, nanoscale resonators exhibit quantum behaviour. NEMS resonators require readout of ultra-small, atomic scale displacements. To achieve this at low temperatures we have developed an ultrasensitive nanoSQUID readout of a coupled current-carrying NEMS resonator. The NanoSQUIDs are fabricated by gallium focussed ion beam milling and are based on niobium nanobridge weak links (Dayem bridges). The nanoSQUIDs have low loop inductance and low junction capacitance resulting in high flux and energy sensitivity. This work focusses on the characterisation of the resonator and nanoSQUID after they have been incorporated onto one chip. This is done through nanoindentation to characterise resonators and electronic measurements of the SQUID using a low-temperature preamplifier. It is found that the model used based upon an Euler-Bernoilli beam is correct close the centre of the sample but does not fit data points well close to the contacts. It is found the resonators have Young’s modulus in the range of 3GPa-241GPa. Both beam and paddle-shaped resonators are investigated and the models are made based upon the two different shapes. That for the paddle is based upon the same as the beam but uses a rectangular function to describe the changing area moment of inertia along the length of the resonator. The SQUID devices are characterised and found to have a typical noise floor of 0.2μ 0/pHz. Problems which have arisen due to the orientation of the two magnetic fields and their effect on the SQUID performance are discussed. We consider the geometry and optimum coupling of rectangular and square Si3N4 resonators to matching similar shaped nanoSQUID loops. We also discuss simulations of the nanoSQUID response versus resonator position for both symmetric and asymmetric configurations. It is found that optimal coupling is achieved in the asymmetric case due to the cancelling of the change in flux in the symmetric case. The use of a normal conducting or superconducting resonator is compared. It is found that a superconducting resonator provides a much larger SQUID response when actuated towards the device but cannot be used in the regime due to limitations of the superconducting transition temperature of Al (the resonator) being lower than the non-hysteretic operable temperature of the SQUID. Preliminary measurements are conducted on the coupled devices. It is noted that the signal from the device in the conducting case may be read out at 2! due to the sinusoidal change in flux through the SQUID loop and position of the resonator. The possibility of measuring such a signal is first investigated using a spectrum analyser but it is found the SQUID is pushed to nonlinear regions of its transfer curve. This results in a component of the signal at 2! due to the nonlinearity of the SQUID response. Conditions under which the SQUID is still operating in small signal mode (to preserve linearity of the SQUID response) are considered and from this we conclude there is a need to use phase sensitive detection to achieve optimum sensitivity. This technique is used to conduct the final measurement of the motion of the resonator by the SQUID and a preliminary result is found.

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Hill, Martyn. "Ultrasonic resonators for particle manipulation." Thesis, University of Southampton, 2004. https://eprints.soton.ac.uk/46529/.

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Ultrasonic standing waves can be used to generate radiation forces which act on particles within a fluid. These forces may be useful for manipulation, separation, or fractionation of these particles. This thesis describes the use and modelling of a number of devices which use such acoustic radiation forces. Initially, the design and testing of a large (multiple wavelength) flow-through ultrasonic separation device is described. This device demonstrated for the first time that flow-through ultrasonic filtration could be made to work successfully on this scale without having to rely on acoustically transparent membranes. Three models are used to examine the behaviour of the resonator. The electro-acoustic model is then used to analyse the performance of two smaller resonators and is shown to match experimental values well. The model is used to explain the behaviour of the resonators in the regions where individual layers of the device themselves have thickness resonances at similar frequencies. It also demonstrates the importance of the bonding between layers and shows that the standing wave at a peak of the energy density response differs, in terms of nodal position and boundary impedance, from simple, rigid-rigid boundary models. The remainder of the thesis concentrates on the design and use of micro-scale devices in which the scale of the layers is similar to or smaller than the wavelengths in use. A novel microfabricated filtration device is described which is primarily constructed using silicon and Pyrex. The modelling, design, fabrication and initial testing of the device are discussed. An expanded version of the electro-acoustic model allows prediction of the radiation forces on an example particle within a standing wave field. This is used to examine the force profile on a particle at resonances with pressure nodes at different positions. An analytical method for predicting modal conditions for combinations of frequencies and layer thickness characteristics is presented, which predicts that resonances can exist that will produce a pressure node at arbitrary positions in the fluid layer of such a system. The model also predicts conditions for multiple sub-wavelength resonances within the fluid layer of a single resonator, each resonance having different nodal planes for particle concentration. This forms the basis for the design of a unique microfabricated resonator with several modes that allow particles to be forced to either boundary of the fluid or to the fluid centre, depending on the operating frequency.

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Cognee, Kevin. "Hybridization of open photonic resonators." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0002.

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Le contrôle de l'interaction entre la lumière et la matière est d'une importance capitale dans de nombreuses technologies modernes, avec des applications allant de la détection, aux télécommunications et à l'information quantique. Les résonateurs nanophotoniques permettent d'améliorer cette interaction par le confinement et le stockage du champ lumineux.Cette thèse étudie l'hybridation des modes propres des nano et microrésonateurs, et en particulier les propriétés de résonateurs hybrides composés d'une cavité diélectrique et de nanoantennes plasmoniques. Les résonateurs photoniques présentent toujours des pertes, en particulier par rayonnement, et ainsi, ne peuvent être bien décrits que dans le cadre de la théorie des modes quasi-normaux (quasinormal modes - QNM). Nous confirmons la pertinence de telles théories en étudiant numériquement et expérimentalement la perturbation de cavités diélectriques à facteurs de qualité élevés.Ensuite, nous proposons une théorie permettant d’étudier l'hybridation de plusieurs résonateurs pour ainsi prédire les propriétés de l’ensemble. Dans le cas d’hybrides antenne-cavité, des travaux antérieurs ont démontré le grand potentiel de ce type de résonateurs pour améliorer l'interaction lumière-matière au-delà de ce qui accessible avec leurs composants pris individuellement. Nous montrons ici, par le biais de travaux théoriques et expérimentaux, que ces résonateurs offrent également des degrés de contrôle supplémentaires sur les propriétés de la lumière émise, telles que la directionnalité, ou encore l’émission d’ondes présentant un moment angulaire orbital pur. Enfin, nous étudions les performances de tels résonateurs hybrides dans le cadre de l'optomécanique moléculaire. En effet, nous montrons qu'ils constituent une excellente plateforme pour augmenter la diffusion Raman, tout en offrant des canaux d’excitation et d’émission dont les propriétés peuvent-être contrôlées, pour les signaux de pompe et Raman
The control of the interaction between light and matter is of paramount importance in many modern technologies, with applications ranging from sensing to telecommunication and quantum information. Nanophotonic resonators allow to enhance this interaction by the storage and confinement of the light field.This thesis studies the hybridization of eigenmodes of nano- and microresonators, and in particular the properties of hybrid resonators composed of a dielectric cavity and plasmonic nanoantennas. Due to their lossy nature, in particular radiation, photonic resonators can only be well described in the framework of quasinormal modes theory (QNM). We confirm the relevance of such theories by investigating the physics of the perturbation of high-Q dielectric cavities aided by numerical and experimental works.Then we propose a theory to study the hybridization of multiple resonators and predict the properties of the ensemble. In the context of antenna-cavity hybrids, previous works have demonstrated the great potential of such resonators to enhance light-matter interaction further than what is achieved with their components taken individually. Here we show, with theoretical and experimental works that such resonators also offer additional degrees of control over the properties of the emitted light, such as directionality or beams carrying a pure orbital angular momentum. We furthermore investigate the performances of such hybrid resonators in the context of molecular optomechanics. Indeed, we show they can be an excellent platform to enhance Raman scattering, while simultaneously offering input and output channels with controllable properties for the pump and Raman signals

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Vidal, Diego N. Guerra. "Noise in nonlinear nonoelectromechanical resonators." Thesis, Boston University, 2013. https://hdl.handle.net/2144/12770.

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Thesis (Ph.D.)--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.
Nano-Electro-Mechanical Systems (NEMS), due to their nanometer scale size, possess a number of desirable attributes: high sensitivity to applied forces, fast response times, high resonance frequencies and low power consumption. However, ultra small size and low power handling result in unwanted consequences: smaller signal size and higher dissipation, making the NEMS devices more susceptible to external and intrinsic noise. The simplest version of a NEMS, a suspended nanomechanical structure with two distinct excitation states, can be used as an archetypal two state system to study a plethora of fundamental phenomena such as Duffing nonlinearity, stochastic resonance, and macroscopic quantum tunneling at low temperatures. From a technical perspective, there are numerous applications such nanomechanical memory elements, microwave switches and nanomechanical computation. The control and manipulation of the mechanical response of these two state systems can be realized by exploiting a (seemingly) counterintuitive physical phenomenon, Stochastic Resonance: in a noisy nonlinear mechanical system, the presence of noise can enhance the system response to an external stimulus. This Thesis is mainly dedicated to study possible applications of Stochastic Resonance in two-state nanomechanical systems. First, on chip signal amplification by 1/fα is observed. The effectiveness of the noise assisted amplification is observed to decrease with increasing α. Experimental evidence shows an increase in asymmetry between the two states with increasing noise color. Considering the prevalence of 1/fα noise in the materials in integrated circuits, the signal enhancement demonstrated here, suggests beneficial use of the otherwise detrimental noise. Finally, a nanomechanical device, operating as a reprogrammable logic gate, and performing fundamental logic functions such as AND/OR and NAND/NOR. is presented. The logic function can be programmed (from AND to OR) dynamically, by adjusting the resonator's operating parameters. The device can access one of two stable steady states, according to a specific logic function; this operation is mediated by the noise floor, which can be directly adjusted, or dynamically "tuned" via an adjustment of the underlying nonlinearity of the resonator. The demonstration of this reprogrammable nanomechanicallogic gate affords a path to the practical realization of a new generation of mechanical computer.

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30

Ergül, Adem. "Fabrication and Characterization of Superconductive Coplanar Waveguide Resonators : Fabrication and Characterization of Superconductive Coplanar Waveguide Resonators." Licentiate thesis, KTH, Applied Physics, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10419.

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The objective of this thesis is to evaluate a generic process for fabrication and characterization of the Superconductive coplanar waveguide (CPW) resonators. Superconductive CPW resonators with various lengths and shapes are designed to investigate their electrical and magnetic properties as well as resonance properties and sensitivities. In the first part of thesis, two different models are introduced in order to estimate the nonlinear kinetic inductance of a superconducting CPW resonator. The first model is based on Bean critical-state model and the second one is based on current dependence of London penetration depth. The existence of a shift in resonant frequency of Superconductive CPW resonator caused by a non-linear kinetic inductance is also shown experimentally. Simulations were carried out to estimate the nonlinear kinetic inductance due to the self- induced magnetic field penetration.

The rest of the thesis is concerned with development of very smooth Aluminum (Al) thin films with RMS (Root Mean Square) roughness 1~nm and CAD (Computer Aid Design) of superconductive CPW resonators. Experimental investigation of a generic fabrication technique for superconductive CPW resonator is carried out. Many resonators are fabricated with different design parameters, such as centerline or gap width, film thickness and gap capacitors length. The fabrication process is described in detail. Electron Beam Lithography is used to fabricate Nb and Al CPW resonators which are coupled to outer conductors via gap capacitors. We have fabricated GHz frequency CPW resonators with quality factors, Q up 5X10^5.

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31

Rabady, Rabi Ibrahim. "Waveguide grating mirror for laser resonators." Connect to online resource - WSU on-site and authorized users, 2003.

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32

Bhaskaran, Harish. "Nanomechanical resonators towards single spin sensitivity." College Park, Md. : University of Maryland, 2006. http://hdl.handle.net/1903/3877.

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Thesis (Ph. D.) -- University of Maryland, College Park, 2006.
Thesis research directed by: Mechanical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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Unterreithmeier, Quirin. "Gradient Field Transduction of Nanomechanical Resonators." Diss., lmu, 2010. http://nbn-resolving.de/urn:nbn:de:bvb:19-122076.

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34

Ibrahim, Tarek A. "Nonlinear optical semiconductor micro-ring resonators." College Park, Md. : University of Maryland, 2003. http://hdl.handle.net/1903/269.

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Thesis (Ph. D.) -- University of Maryland, College Park, 2003.
Thesis research directed by: Electrical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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Udaiyan, Darren. "Novel self-adaptive Nd:YAG laser resonators." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300857.

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Alkov, Steven L. "Multifrequency acoustic resonators with variable nonuniformity." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/28380.

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Wasilewski, Bartosz. "Novel resonators for planar waveguide lasers." Thesis, Heriot-Watt University, 1999. http://hdl.handle.net/10399/1221.

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Wong, Seck Jiong. "Thermoelastic damping in MEMS ring resonators." Thesis, University of Nottingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431849.

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Burg, Thomas P. (Thomas Peter). "Suspended microchannel resonators for biomolecular detection." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/34471.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.
Includes bibliographical references (leaves 115-124).
Microfabricated transducers enable the label-free detection of biological molecules in nanoliter sized samples. Integrating microfluidic detection and sample-preparation can greatly leverage experimental efforts in systems biology and pharmaceutical research by increasing analysis throughput while dramatically reducing reagent cost. Microfabricated resonant mass sensors are among the most sensitive devices for chemical detection, but degradation of the sensitivity in liquid has so far hindered their successful application in biology. This thesis introduces a type of resonant transducer that overcomes this limitation by a new device design: Adsorption of molecules to the inside walls of a suspended microfluidic channel is detected by measuring the change in mechanical resonance frequency of the channel. In contrast to resonant mass sensors submersed in water, the sensitivity and frequency resolution of the suspended microchannel resonator is not degraded by the presence of the fluid. Our device differs from a vibrating tube densitometer in that the channel is very thin, and only molecules that bind to the walls can build up enough mass to be detected; this provides a path to specificity via molecular recognition by immobilized receptors.
(cont.) Suspended silicon nitride channels have been fabricated through a sacrificial polysilicon process and bulk micromachining, and the packaging and microfluidic interfacing of the resonant sensors has been addressed. Device characterization at 30 mTorr ambient pressure reveals a quality factor of more than 10,000 for water filled resonators; this is two orders of magnitude higher than previously demonstrated Q-values of resonant mass sensors for biological measurements. Calculation of the noise and the sensitivity of suspended microchannel resonators indicate a physical limit for mass resolution of approximately 0.01 ng/cm2 (1 Hz bandwidth). A resolution of -0.1 ng/cm2 has been experimentally demonstrated in this work. This resolution constitutes a tenfold improvement over commercial quartz crystal microbalance based instruments. The ability to detect adsorbing biomolecules by resonance frequency has been validated through binding experiments with avidin and various biotinylated proteins.
by Thomas P. Burg.
Ph.D.

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40

Childs, James Joseph. "Atom-field interaction in optical resonators." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/38422.

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Diao, M'baye S. M. Massachusetts Institute of Technology. "Investigation of resonators loaded periodic structures." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35606.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.
"February 2006."
Includes bibliographical references (leaves 71-74).
The study of metamaterials has brought about new changes in modern microwave communication systems. As predicted by Veselago some 37 years ago, substances which exhibit simultaneously, negative permittivity ([epsilon]) and negative permeability ([mu]) over a certain range of frequencies would display some unusual phenomena such as backward waves, reversed refraction, backward Cerenkov radiation, and negative refractive index. Because of these new features of left handed materials, many structures such as split rings resonators (SRR) have been proposed in the literature to artificially fabricate radio frequency and microwave components. Due to their bulk properties, periodic arrays of SRRs provide a negative permeability. Therefore under the fundamental limit of effective medium theory that the dimensions of the lattice are much smaller than the wavelength, we can treat the array of SRRs as bulk material and retrieve its effective parameters.
(cont.) Also because of size reduction and selective passband transmission spectra in planar geometry, split rings resonators are designed under the fundamental limit (dimensions of one-tenth of the wavelength or smaller), and as a result they constitute better candidates than their L-C loaded transmission lines counterparts for microwaves applications. The generalized formula for impedance-loaded transmission line is derived. The dispersion characteristic and impedance of structures with periodic resonators are analyzed as well.
by M'baye Diao.
S.M.

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Wang, Wentao Ph D. Massachusetts Institute of Technology. "Solid State MEMS Resonators in Silicon." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/100152.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 191-196).
Two of the greatest challenges in MEMS are those of packaging and integration with CMOS technology. Development of solid state RF MEMS resonators in silicon, resonators that do not require any release etch step, eliminates the necessity for complex encapsulation methods and costly packaging. Such solid state solution could also enable direct integration into front-end-of-line (FEOL) processing in CMOS, making these devices an attractive choice for on-chip signal generation and signal processing. This thesis discusses the physics, design considerations, and process developments to build such solid state MEMS resonators in silicon, showing a series of incremental stages of the prototyping of such devices. The major challenge of building solid state MEMS resonators lies in maintaining comparable device performance relative to released ones, especially quality factor Q. Energy localization structures, such as acoustic Bragg reflectors (ABRs) are implemented for such solid state resonators to maintain high Q and suppress spurious modes. Towards the goal of high aspectratio structures that have the capability of direct CMOS integration, deep trench (DT) capacitor based MEMS resonators are studied and demonstrated. This concept enables high Q, low loss multi-GHz resonators in a simple, robust manufacturing process.
by Wentao Wang.
Ph. D.

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Calhoun, Paul Jacob 1979. "Frequency synthesis using MEMS piezoelectric resonators." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28897.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004.
Includes bibliographical references (p. 79).
(cont.) Ultimately, this thesis presents two approaches to frequency synthesizer design. The first uses frequency windows of approximately 200 MHz. The 800 MHz to 1 GHz matching network is presented in detail along with predicted performance capabilities across this frequency range. The second design implements matching networks with variable capacitors and a variable load impedance. CAD performance simulations validate the broadband switched array design concept, and represent a first step towards realizing a new, commercially viable RF MEMS oscillator and switched array frequency synthesizer. The views expressed in this article are those of the author and do not reflect the official policy or position of the United States Air Force, Department of Defense, or the U.S. Government.
This thesis explores the foundational issues in oscillator and frequency synthesizer design using an integrated MEMS piezoelectric resonator. It presents an original low phase-noise oscillator design and two frequency synthesizer designs using the emerging technology of Draper Laboratory's MEMS GHz-range resonator. The designs leverage the extremely small size and high Q of this MEMS resonator to develop integrable, energy efficient, low phase noise oscillators and frequency synthesizers. The circuits presented offer significant size and flexibility advantages over present designs, while promising exceptional performance. First, a 1 GHz frequency oscillator design is described incorporating the longitudinal mode bar (L-Bar) resonator with a SiGe bipolar junction transistor (BJT) in a one-port reflection topology. This design choice was made to minimize circuit complexity when later employed in a frequency synthesizer with a broadband array of switched resonators. Harmonic frequency matching is considered in a trade study between phase noise, efficiency, and circuit complexity. Performance was further enhanced using a novel approach for selecting the target static negative impedance looking into the transistor. This method modifies the transistor base current and matching networks in a manner that allows simultaneous optimization of phase noise and efficiency. The resulting oscillator has size and predicted performance characteristics that are unachievable using present technology. Second, the matching networks from the 1 GHz oscillator are altered to allow for oscillation over a frequency range selected by an array of switched resonators. The resulting frequency synthesizer is designed to operate in the range of 200 MHz to 1 GHz.
by Paul Jacob Calhoun.
S.M.

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Wimberley, Jack Timpson. "Behavior of Periodic Coupled Microstrip Resonators." Thesis, Boston College, 2011. http://hdl.handle.net/2345/1983.

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Thesis advisor: Krzysztof Kempa
The resonant modes of a sequence of periodically spaced microstrip resonators is studied. The system is analyzed as transmission line with periodic capacitive gaps, as a waveguide with apertures via normal mode expansion, and through a derivation of the static fields in the gap between two microstrip resonators via conformal mapping. FDTD simulations are also performed to numerically calculate the resonant modes of the sequence and also its absorption spectrum when it contains a lossy dielectric. It is found, as expected, that when the gap size is large, the microstrip resonators are uncoupled and there resonant modes are unperturbed. As the gap size narrows, the resonators become strongly coupled, and changing boundary conditions perturb the resonant modes upwards in frequency. Moreover, an additional resonant mode is observed that does not correspond to any uncoupled mode
Thesis (BS) — Boston College, 2011
Submitted to: Boston College. College of Arts and Sciences
Discipline: College Honors Program
Discipline: Physics Honors Program
Discipline: Physics

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45

Slawik, Alexander John. "Nonlinear Analysis of Silicon Microdisk Resonators." Thesis, Northwestern University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3741327.

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This dissertation addresses the character, control, and application of self-sustained oscillations in two-photon absorption dominated optical cavities. The complex interactions of photons, electrons, and thermal effects are understood to drive these emergent oscillations, with the dynamics captured by a system of ordinary differential equations. First, I explore the dynamics of the model and characterize the emergent optical oscillations as relaxation oscillations of a fast-slow system under certain conditions. Within this framework, I establish the entrainment of the oscillations to periodic forcing, providing an easy mechanism for control. The model is further extended to an opto-mechanical system which can be used as a sensor for atomic force microscopy. Analysis of the system predicts that two-photon absorption based effects can excite the mechanical modes of the sensor and increase the signal to noise ratio of the optical readout.

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Elliott, Gregor Robert. "Optical micro-resonators in chalcogenide glass." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/70912/.

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This thesis focuses on the production of gallium lanthanum sulphide (GLS) microspheres and their potential uses. Microspheres, and micro-resonators in general, have attracted considerable attention because of their promise in all-optical-switching, micro-lasers, multiplexers and many other applications. In this thesis, several applications have been investigated, culminating in the demonstration of laser action in a neodymium doped GLS microsphere. The possibility of using microspheres as ball lenses has been investigated and shown to be possible. Laser action was observed in a neodymium doped GLS microsphere. The laser had a threshold of 83mW of incident pump power, with a peak at 1082nm and a line width of <0.05nm

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Busse, Mark A. "Characterization of materials using stripline resonators." Thesis, Virginia Tech, 1989. http://hdl.handle.net/10919/45954.

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This thesis describes a method for using stripline resonators to characterize the electrical properties of materials used in the construction of planar geometry transmission lines and circuits. The method characterizes both dielectric and conductor materials. It can be used to find the relative dielectric constant and to separate the conductor and dielectric losses. The separation of the loss terms is achieved by fitting measurements of stripline losses to a well known model. This model identifies the loss terms separately based on variation of the losses with stripline dimensions.

This thesis presents the complete stripline resonator model used. The model has been incorporated into a computer simulation which predicts the resonator response. This simulation is useful in many ways, including the design of various resonators needed in experiments. Also presented are the results of an experiment which demonstrates the feasibility of this method when applied to real samples. These results show that this method works well for low loss materials.

Further development may produce 6 model which will allow this method to be used on higher loss materials. A similar theoretical derivation may be used to develop a model for using this method with other transmission line structures such as coaxial lines. This method is advantageous because it does not assume that material properties are independent of frequency and can be designed to produce results at a specific frequency. Stripline resonators are easily manufactured and a network analyzer is the only test equipment required. For these reasons, this method can be used to provide accurate results at a low cost.

Master of Science

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Gao, Jiansong Zmuidzinas Jonas Zmuidzinas Jonas. "The physics of superconducting microwave resonators /." Diss., Pasadena, Calif. : California Institute of Technology, 2008. http://resolver.caltech.edu/CaltechETD:etd-06092008-235549.

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Chandorkar, Saurabh Arun. "Energy loss mechanisms in micromechanical resonators /." May be available electronically:, 2009. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.

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Cousins, Richard. "Fabrication and measurement of nanomechanical resonators." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/39302/.

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Over the past years there has been great progression in the field of micro- and nanomechanics with devices with higher and higher Q factors being created. This has been made possible thanks to a combination of advances in fabrication techniques and an increase in understanding as to what causes dissipation in nanometre scale structures. This understanding of dissipation mechanisms is still incomplete however. While lots of work has been done investigating mechanisms such as thermoelastic dissipation and dissipation due to two level systems (TLS) within the standard tunnelling model (STM) a full understanding has not been forthcoming. The increase in the quality of nanomechanical systems has allowed them to be coupled to optical or microwave cavities allowing the position of the mechanical system to be measured with near quantum limited accuracy. This thesis looks at both these streams of research within nanomechanics. It looks at the fabrication of silicon nitride torsional resonators that can have either their flexural or torsional modes preferentially actuated via a piezoelectric drive. It was found for a single paddle resonator that the room temperature Q factor of the flexural mode was 2870±70 and for the torsional mode was 5050±220. It was shown that while thermoelastic damping was reduced in the torsional mode it was still present meaning that we could not use the model for a simple beam to describe thermoelastic damping for a paddle resonator. The properties of an nanomechanical beam fabricated from a single crystal of aluminium were also investigated. It was found that at 1.5 K it had an unloaded Q factor of 36900 which is at least 2 times larger then any other group has reported. We also used our knowledge of high stress silicon nitride membranes to design a system that could couple an aluminium on silicon nitride membrane to a LCR circuit. Calculations show that this would have a coupling constant, g, of over 1000 putting it well within the regime where ground state cooling and quantum limited measurements are possible.

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Dissertations / Theses on the topic 'Resonators'

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