This dissertation presents the investigation of novel electromagnetic structure, circuit, and material for microwave engineering. There are four topics covered in this work: the study of a waveguide filter at W-band frequencies using electromagnetic crystal (EMXT) surfaces, the design of a dual-band amplifier with flexible frequency ratio, the analysis and testing of a compact 4:1 planar combiner with complex matching, and the investigation of a dielectric nanostructured material using a mixture of polymer and silver nanoparticles. First, a rectangular waveguide band-stop filter using electromagnetic crystal EMXT surfaces is presented. A waveguide is loaded on the top and/or the bottom walls with EMXT surface, which has a propagating band gap. An equivalent circuit is developed to model the filter behavior and to predict its stop band. A W-band prototype based on the proposed filter architecture is designed and tested. The experimental results show a rejection band centered at 97 GHz and a rejection level of 16 dB. Second, a dual-band amplifier is demonstrated with flexible frequency ratios. The proposed amplifier features novel dual-band Wilkinson power divider/combiner that allows large frequency ratios between the first and second bands (2.16 to 4.9) between the first and second operating frequencies. The stand-alone combiner has maximum potential combining efficiency of 95% and 75% at the first and second frequency bands, respectively. A 2.4 / 5.8 GHz prototype amplifier is tested to verify its dual-band functionality. Measured linear gains are 12.85 dB and 11.09 dB at the first and second frequency bands, respectively. Third, a “spatial” combiner inspired power combiner / divider for solid-state amplifier application is presented. The proposed “one-stage” combining is realized by a single port tapered to an oversized microstrip connecting to parallel multiport microstrip sections. Uniform amplitude/phase and complex impedance matching at the parallel multiport microstrips are simultaneously achieved by adjusting the geometry of the structure. A prototype 5 GHz 1-to-4 divider/combiner designed using ADS co-simulation is characterized. The measured combining efficiency of 82.4% is achieved at 5 GHz. Lastly, a nanostructure thin film with giant dielectric response is proposed by strategically dispersing silver nano-particles inside a Tropropylene glycol diacrylate (TRPGDA) polymer. The dielectric properties of the proposed thin film are experimentally extracted at the microwave frequencies. The measurement sample is prepared by laying a coplanar waveguide (CPW) line on the thin film that is supported by a glass substrate. Two-port S-parameter measurements on the CPW are performed. Dispersion mechanism due to internal inductance of the CPW line when calculating the effective dielectric constant is investigated. The extraction involves conformal mapping approximation that uses closed-form equations to calculate the dielectric constant and the loss tangent of each layer based on the effective dielectric constant and loss tangent of the entire structure. Alternatively, direct fitting technique using simulation to model the experiment is studied. The results of the two techniques are compared and discussed. The measured dielectric constant ranges from 30000 to 4600 from 1 to 20 GHz with a loss tangent of 0.55 to 1.75 from 1 to 20 GHz.

Recientes descubrimientos han hecho posible la creación de un nuevo tipo de materiales: los metamateriales. En sólo algunos años, el desarrollo de esta nueva rama científica ha dado lugar a numerosos descubrimientos y avances tecnológicos basados en las nuevas propiedades que exhiben estos nuevos materiales. Esta tesis recoge parte del trabajo desarrollado durante los últimos años por el grupo GEMMA y CIMITEC en la aplicación de líneas de transmisión de tipo resonante en el desarrollo de dispositivos de microondas. Su pequeño tamaño y la controlabilidad de sus propiedades eléctricas son las principales propiedades de las líneas metamaterial basadas en resonadores concentrados que posibilitan su empleo en el diseño de dispositivos de microondas de pequeñas dimensiones. Estos dispositivos son de interés especialmente en aquellas aplicaciones en las que un reducido tamaño es un requerimiento importante. No obstante, además de su reducido tamaño, dichos dispositivos pueden ofrecer mejoras en su respuesta y e incluso nuevas funcionalidades. El documento ha sido escrito como compendio de 13 artículos. Dichos artículos contienen gran parte de los resultados desarrollados durante la realización de esta tesis y se detallan en una lista más adelante. El documento se ha dividido en varias secciones dedicadas a diferentes aspectos: -En el segundo capítulo se presenta una breve introducción sobre metamaterials y materiales zurdos, incluyendo sus propiedades y sus elementos constitutivos. Se dedica una especial atención a la aplicación de dichos conceptos a estructuras planares y la síntesis de líneas de transmisión metamaterial. -El tercer capítulo trata sobre la implementación de líneas de transmission metamaterial mediante el modelo resonante, que es el empleado en este trabajo. Se presentan y estudian diferentes tipos de líneas de transmission metamaterial, con especial énfasis en las estructuras empleadas en las aplicaciones presentadas en el capítulo 4. -El cuarto capítulo se dedica a las aplicaciones de las estructuras ya presentadas al diseño de components concretos, incluyendo diferentes tipos de divisors de potencia, filtros de banda ancha y estrecha y estructuras reconfigurables basadas en materiales ferroeléctricos. -Por ultimo, el quinto capítulo incluye las conclusions y posibles futuros objetivos. ARTÍCULOS: Debido a la normative, los artículos marcados con un asterisco (*) no pueden ser considerados como parte fundamental de esta tesis, bien por ser artículos presentados a conferencias especializadas en lugar de revistas de investigación, o pore star pendientes de publicación en el momento del depósito de esta tesis. -Article A: M. Gil, J. Bonache, I. Gil, J. García-García and F. Martín, "On the transmission properties of left handed microstrip lines implemented by complementary split rings resonators", Int. Journal Numerical Modelling: Electronic Networks, Devices and Fields, vol. 19, pp 87-103, 2006. -Article B: M. Gil, J. Bonache, I. Gil, J. García-García and F. Martín, "Miniaturization of planar microwave circuits by using resonant-type left handed transmission lines", IET Microwave Antennas and Propagation, Vol.1, pp. 73-79, 2007. -Article C: M. Gil, I. Gil, J. Bonache, J. García-García and F. Martín, "Metamaterial transmission lines with extreme impedance values", Microwave and Optical Technology Letters, vol. 48, pp. 2499-2505, 2006. -Article D*: M. Gil, J. Bonache, I. Gil, J. García-García and F. Martín, "Artificial Left¬handed Transmission Lines for Small Size Microwave Components: Application to Power Dividers", presented at 36th European Microwave Conference (EuMC), Manchester (UK), pp. 1135-1138, 2006. -Article E: M. Gil, J. Bonache, J. Selga, J. García-García, F. Martín, "Broadband resonant type metamaterial transmission lines ", IEEE Microwave and Wireless Components Letters, vol. 17, pp. 97-99, 2007. -Article F: M. Gil, J. Bonache, J. García-García, J. Martel and F. Martín, "Composite Right/Left-Handed Metamaterial Transmission Lines Based on Complementary Split-Rings Resonators and Their Applications to Very Wideband and Compact Filter Design", IEEE Transactions on Microwave Theory and Techniques, Vol. 55, No. 6, pp. 1296-1304, 2007. -Article G: M. Gil, J. Bonache, F. Martín, "Metamaterial Filters with Attenuation Poles in the Pass Band for Ultra Wide Band Applications", Microwave and Optical Technology Letters, Vol. 49, Issue 12, pp 2909-2913, 2007. -Article H : M. Gil, J. Bonache, J. García-García and F. Martín, "New Left Handed Microstrip Lines With Complementary Split Rings Resonators (CSRRs) Etched in the Signal Strip", IEEE MTT-S Int'l Microwave Symposium Digest, Honolulu (HA), USA, pp. 1419-1422, 2007. -Article I: M. Gil, J. Bonache and F. Martín, "Synthesis and applications of new left handed microstrip lines with complementary split-ring resonators etched on the signal strip", IET Microwaves, Antennas & Propagation, Vol. 2, Issue 4, pp. 324-330, 2008. -Article J: J. Bonache, M. Gil, O. García-Abad and F. Martín, "Parametric analysis of microstrip lines loaded with complementary split ring resonators", Microwave and Optical Technology Letters, Vol. 50 , Issue 8, pp. 2093-2096, 2008. -Article K*: M. Gil, J. Bonache, F. Martín. "Ultra Compact Band Pass Filters Implemented Through Complementary Spiral Resonators (CSRs)", IEEE MTT-S Int'l Microwave Symposium Digest, Atlanta, USA, pp.323-326, 2008. -Article L: M. Gil, J. Bonache, and F. Martín, "Metamaterial filters: A review", Metamaterials, vol. 2, pp. 186-197, 2008. -Article M*: M. Gil, C. Damm, A. Giere, M. Sazegar, J. Bonache, R. Jakoby, F. Martín. "Electrically Tunable SRRs at Microwave frequencies based on BST thick films". Electronic Letters (submitted). / Recent advances have made possible the emergence of a new kind of materials: Metamaterials. In just some years, the development of this new scientific branch has given rise to numerous discoveries and technological advances based on the new properties shown by these novel materials. The present Thesis gathers a part of the work developed during the last years in the Group GEMMA and CIMITEC in the application of resonant-type metamaterial transmission lines to the development of microwave devices. The small size and the controllability of the electrical characteristics of metamaterial transmission lines based on sub-wavelength resonators are the main properties that make possible their use in the synthesis of microwave devices with compact dimensions and exceptional features. Microwave components based on metamaterial transmission lines are, therefore, of special interest in those applications in which compactness is a critical aspect. However, besides their small size, such devices can also offer a performance improvement or even new functionalities. This document has been written as a compendium of 13 articles. The articles contain most of the results of the work developed during the realisation of this Thesis and are included in a complete list given below. The document has been divided in several sections devoted to different aspects: -The second chapter presents a brief introduction about Metamaterials and left-handed materials, including their properties and constituent elements. Special attention is paid to the application of such concepts to planar structures and the synthesis of metamaterial transmission lines. -The third chapter delves into the implementation of metamaterial transmission lines by means of the resonant approach, which is applied in this work. Different kinds of resonant-type metamaterial transmission lines are presented and studied, with special emphasis on those structures which have been employed in the devices presented in chapter 4. -The fourth chapter is devoted to the applications of the previously studied structures to the design of specific components, including different kinds of power dividers, narrow- and broad-band filters and reconfigurable structures based on ferroelectric materials. -Finally, the fifth chapter includes some conclusions and possible next goals are exposed. ARTICLES: Due to regulation reasons, the articles marked with * cannot be considered as a basic part of this Thesis, either for being Conference, but not Journal Articles, or for being pending acceptance by the time of the Thesis submission. -Article A: M. Gil, J. Bonache, I. Gil, J. García-García and F. Martín, "On the transmission properties of left handed microstrip lines implemented by complementary split rings resonators", Int. Journal Numerical Modelling: Electronic Networks, Devices and Fields, vol. 19, pp 87-103, 2006. -Article B: M. Gil, J. Bonache, I. Gil, J. García-García and F. Martín, "Miniaturization of planar microwave circuits by using resonant-type left handed transmission lines", IET Microwave Antennas and Propagation, Vol.1, pp. 73-79, 2007. -Article C: M. Gil, I. Gil, J. Bonache, J. García-García and F. Martín, "Metamaterial transmission lines with extreme impedance values", Microwave and Optical Technology Letters, vol. 48, pp. 2499-2505, 2006. -Article D*: M. Gil, J. Bonache, I. Gil, J. García-García and F. Martín, "Artificial Left¬handed Transmission Lines for Small Size Microwave Components: Application to Power Dividers", presented at 36th European Microwave Conference (EuMC), Manchester (UK), pp. 1135-1138, 2006. -Article E: M. Gil, J. Bonache, J. Selga, J. García-García, F. Martín, "Broadband resonant type metamaterial transmission lines ", IEEE Microwave and Wireless Components Letters, vol. 17, pp. 97-99, 2007. -Article F: M. Gil, J. Bonache, J. García-García, J. Martel and F. Martín, "Composite Right/Left-Handed Metamaterial Transmission Lines Based on Complementary Split-Rings Resonators and Their Applications to Very Wideband and Compact Filter Design", IEEE Transactions on Microwave Theory and Techniques, Vol. 55, No. 6, pp. 1296-1304, 2007. -Article G: M. Gil, J. Bonache, F. Martín, "Metamaterial Filters with Attenuation Poles in the Pass Band for Ultra Wide Band Applications", Microwave and Optical Technology Letters, Vol. 49, Issue 12, pp 2909-2913, 2007. -Article H : M. Gil, J. Bonache, J. García-García and F. Martín, "New Left Handed Microstrip Lines With Complementary Split Rings Resonators (CSRRs) Etched in the Signal Strip", IEEE MTT-S Int'l Microwave Symposium Digest, Honolulu (HA), USA, pp. 1419-1422, 2007. -Article I: M. Gil, J. Bonache and F. Martín, "Synthesis and applications of new left handed microstrip lines with complementary split-ring resonators etched on the signal strip", IET Microwaves, Antennas & Propagation, Vol. 2, Issue 4, pp. 324-330, 2008. -Article J: J. Bonache, M. Gil, O. García-Abad and F. Martín, "Parametric analysis of microstrip lines loaded with complementary split ring resonators", Microwave and Optical Technology Letters, Vol. 50 , Issue 8, pp. 2093-2096, 2008. -Article K*: M. Gil, J. Bonache, F. Martín. "Ultra Compact Band Pass Filters Implemented Through Complementary Spiral Resonators (CSRs)", IEEE MTT-S Int'l Microwave Symposium Digest, Atlanta, USA, pp.323-326, 2008. -Article L: M. Gil, J. Bonache, and F. Martín, "Metamaterial filters: A review", Metamaterials, vol. 2, pp. 186-197, 2008. -Article M*: M. Gil, C. Damm, A. Giere, M. Sazegar, J. Bonache, R. Jakoby, F. Martín. "Electrically Tunable SRRs at Microwave frequencies based on BST thick films". Electronic Letters (submitted).

The main objective of this thesis is to take one step forward to practical and realisable devices for antenna and microwave engineering, using the technique of discrete coordinate transformation (DCT), which is a practical implementation of the coordinate transformation method. During this thesis, the DCT technique was demonstrated and analysed from the theory, and was proved to provide an all-dielectric approach to design devices under certain conditions. Two schemes were proposed on how to use this technique in a practical design. The first one is to transform an existing device into a flattened profile, meanwhile maintaining its electromagnetic performance. As examples, a flat reflector and a flat lens were created from a parabolic reflector and a convex lens, respectively. The second scheme is to project the propagating paths of an electromagnetic wave, and then generate a distorted space according to the paths by engineering the electromagnetic properties of the media. In this scheme, two examples of application were presented: an undetectable antenna composed of a carpet cloak and a conducting cavity, and a broadband device which can extraordinarily enhance the transmission through a sub-wavelength aperture. Numerical simulations based on the Finite-Difference Time-Domain (FDTD) method were implemented to verify all the designs. Several specific configurations were employed in the modelling in order to simulate the DCT based devices more efficiently and precisely. Performance of these devices was validated and analysed, and the advantages and disadvantages of this technique were investigated. Realisation and fabrication methods i were also studied, and a prototype was designed, fabricated and measured. At the end, as an extension, a multiple discrete coordinate transformation method was proposed and presented. This multiple transformation was proved to effectively relax the limitation of the one-step transformation, and was used to design an all-dielectric thin absorber from a conventional pyramidal one for demonstration.

In today’s technologically driven world, antennas play an essential role in enabling wireless communications over long distances and allow communities to interact on a global scale. Typically, this is done using large networks of antenna systems on the ground and in space to ensure signals reliably arrive at their destinations, which can be very expensive in terms of replacement cost and maintenance as the number of nodes increase. We shall be discussing a new method for deploying space-borne antennas via CubeSats that will enable high speed communications with the ground and other satellites at a fraction of the cost and complexity of traditional communication systems. Specifically, the focus will be on the design of a phased array line feed and the backend systems for a CubeSat deployable inflatable spherical reflector that is electronically steerable to any direction in azimuth and elevation.

No description available.

<p> This thesis presents solutions to several inverse problems m electromagnetism and microwave engineering. In general, these inverse problems belong to two applications: breast cancer diagnosis using microwave imaging and defect characterization in metallic structures using magnetic flux leakage (MFL). </p> <p> Our contribution in microwave imaging for breast tumor detection can be divided into three parts. First, we propose a novel ultra-wide band (UWB) antenna that can operate in direct contact with the breast without the need for coupling liquids. This antenna is designed such that more than 90% of the radiated power is directed toward the tissue from its front aperture over the UWB. The performance of the antenna is investigated via simulation and measurement of the following parameters: return loss, near-field directivity, efficiency, fidelity, and group velocity. Overall, the results show that the antenna is a good candidate for frequency and time-domain imaging techniques. </p> <p> Second, we have proposed an aperture raster scanning setup that benefits from the features of our novel antenna. In this scanning setup, the breast tissue is compressed between two rectangular plates (apertures) while two antennas perform two-dimensional (2-D) scan by moving together on both sides of the compressed tissue. For each scanning step, the transmission S-parameter between the two antennas is recorded at several frequencies within UWB. Then, the modulus of the calibrated transmission S-parameter is plotted at each frequency to provide a 2-D image of the interior of the breast. The images are enhanced using a de-blurring technique based on blind de-convolution. This setup provides real time images of strong scatterers inside the normal tissue. </p> <p> Third, we propose 2-D and three-dimensional (3-D) holography algorithms to further improve the quality of the images obtained from the proposed planar scanning setup. These techniques are based on the Fourier transforms of the collected data to provide an image of a 2-D target (when collecting data at a single frequency) or a 3-D target (when collecting wide-band data). These techniques are fast and very robust to noise. The capability of the 2D and 3-D holographic imaging techniques is examined via simulation results. </p> <p> For defect characterization in metallic structures using MFL technique, we propose fast and reliable methodologies to invert the measured MFL response to the defect's shape parameters. First, we present a procedure to estimate the shape parameters of rectangular cracks which are the most common type of defects in the metallic structures. The procedure consists of estimating orientation, length, and depth of the cracks, consecutively. We validate this procedure via estimating the shape parameters of pre-known cracks from the simulated and measured MFL responses. Then, we present a methodology based on space mapping (SM) optimization for defect characterization. We examme the efficiency of this methodology for two types of defects: rectangular cracks and cylindrical pits. </p> / Thesis / Doctor of Philosophy (PhD)

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24584号 / 工博第5090号 / 新制||工||1975(附属図書館) / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 篠原 真毅, 教授 大村 善治, 教授 小嶋 浩嗣, 教授 引原 隆士 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

No description available.

Indiana University-Purdue University Indianapolis (IUPUI) / This thesis proposes a reconfigurable phased array of antennas for wireless power transfer. The array finds use in many applications, from drone destruction (for defense) to wireless charging of robots and mobile devices. It utilizes a novel feeding architecture to greatly reduce the number of high cost elements (such as amplifiers and phase shifters) as well as the quantity of unused resources in the system. Upon the instruction of the CPU, the array can separate into any number of subarrays, each of which transmits power to a single receiver, steering its beam as the receiver changes location. Currently dormant elements in the array can be used to provide position information about the receivers, either via Radar, or by listening for beacons pulses from the receiver. All of this is made possible, with only 4 amplifiers and 3 phase shifters, by the proposed 4-Bus Method. The source signal is divided into four buses, which are respectively phase shifted by 270 degrees, 180 degrees, 90 degrees, and 0 degrees (no shifter required) and then amplified. The CPU calculates, based on the number and positions of the receivers / targets, what the amplitude and phase excitation must be at each element. Any phase and amplitude which could be required can be achieved by simply adding together appropriate quantities of the correct two buses. In order to achieve this, the key piece is the variable power divider. These differ from Wilkinson dividers in that the dividing ratio can be changed via an applied DC voltage. Therefore, at each junction, by properly diverting the power levels on each phase bus to their proper location, complete delocalization of both amplifiers and phase shifters can be achieved. A method has also been developed which helps overcome the limitations of each variable power divider. That is, in certain instances, it may be desirable to pass all the power to a single output port or the other, which is not a possibility inherently possible with the device. With the use of a unique combination of RF switches, the nodes achieve much enhanced flexibility. Finally, an intensive study is carried out, in an attempt to yield greater understanding, as well as quick, useful approximations, of the behaviors of both rectangular and hexagonal arrays of various sizes and beam steering angles for wireless power.

We investigate the resonant characteristics of superconducting meandering nanowires to design a nonlinear kinetic inductance traveling-wave parametric amplifier. The devices are patterned out of 15 nm thick NbTiN films. They consist of a coplanar waveguide, that shrinks into 100 nm wide meandering nanowires. For a total kinetic inductance of ∼1 μH, our simulations show that these structures behave as resonators with fundamental mode frequency around 1 GHz and a phase velocity of the signal as low as c/1000. The resonance peaks correspond to the presence of current antinodes within the meandering structure. Samples were fabricated at the Albanova Nanolab facility and measured in a sample-in-vacuum dipstick at 300 mK. Frequency sweeps in the 0.1-10 GHz range confirm the presence of these resonance peaks. In addition, we investigate the current nonlinearity of our devices. Analysis of the temperature dependence of the resonant peaks revealed the critical temperature of the film, TC = 14.0 ± 0.5 K. The dispersion relations showed that the device impedance exceeds the resistance quantum RQ = 6.5 kΩ when close to resonance or below 87 MHz. A second design was realized in order to reduce the device’s characteristic impedance to ≈ 50 Ω. This design, accomodating a micro stripline, embedded a significantly longer nanowire, with a total kinetic inductance ∼10 μH. Measurements showed a dramatically reduced impedance to ≈ 700 Ω, but still not matched to 50 Ω, giving rise to a dense frequency comb of standing modes in the 0-3 GHz bandwidth, with a constant spacing of ≈ 45 MHz. / Vi undersöker egenskaperna hos supraledande slingrande nanotrådar i syfte att designa en ickelinjär kinetisk induktans parametrisk förstärkare. Våra prov är mönstrade ur 15 nm tjocka NbTiN-filmer. De består av en koplanär vågledare som krymper till 100 nm breda slingrande nanotrådar. Med en sammanlagd kinetisk induktans på ∼1 μH visar våra simuleringar att dessa strukturer beter sig som resonatorer med en funda- mental modfrekvens runt 1 GHz och en fashastighet för signalen så låg som c/1000. Resonanserna motsvarar närvaron av strömantinoder inom den slingrande strukturen. Proverna tillverkades i Albanovas Nanolab och mättes i en prov-i-vakuum-sticka runt 300 mK. Frekvenssvepen i området 0,1-10 GHz bekräftar förekomsten av dessa res- onanser. Dessutom undersökte vi den strömberoende ickelinjäriteten i våra enheter. Analys av resonansernas temperaturberoende ger ett värde på filmens kritiska temper- atur, TC = 14.0 ± 0.5 K. Dispersionsförhållandena visade att provens impedans över- stiger resistanskvantumet RQ = 6, 5 kΩ nära resonanserna. En andra design realiserades för att reducera provens karakteristiska impedans till ≈ 50 Ω. Denna design, med en mikrostripline, har en betydligt längre totaltsträcka med en sammanlagd kinetisk induk- tans på ∼10 μH. Mätningarna visade en dramatiskt reducerad impedans på ≈ 700 Ω, men inte till det matchade värdet på 50 Ω, vilket gav upphov till en tät frekvenskam inom bandbredden 0- 3 GHz, med ett avstånd på ≈ 45 MHz mellan resonanserna.