Recientemente se ha abierto un nuevo campo de investigación en el área del electromagnetismo aplicado y de la ingeniería de microondas basado en el control de las propiedades electromagnéticas de ciertas estructuras periódicas artificiales conocidas como metamateriales. Debido a que las celdas constitutivas de este tipo de estructuras presentan unas dimensiones muy reducidas en términos de longitud de onda es posible diseñar, en base a este concepto, dispositivos que combinen un gran nivel de compactación y elevadas prestaciones. En esta tesis se han utilizado las propiedades de dichos medios para la implementación de filtros de microondas en tecnología planar. Particularmente se han desarrollado técnicas de síntesis que permiten el diseño de filtros con características controlables, en términos de ancho de banda, rizado en la banda de paso, colocación de ceros de transmisión en la banda de rechazo, etc. En este documento se pueden encontrar varios ejemplos de aplicación de estas técnicas, dando lugar a varios prototipos con respuestas en varios rangos de frecuencia, que van desde respuestas de banda estrecha hasta respuestas ultra anchas. / In the last years, a new research field in the area of applied electromagnetism and microwave engineering based on the control of electromagnetic properties of artificial structures has taken a great interest. These structures are known as metamaterials. Due to the small dimensions of its constitutive cells it is possible to design, based on this concept, devices that combine high performance and compact dimensions. This thesis concerns the application of metamaterial technology to the synthesis of microwave filters in planar technology. In this document can be found a design methodology for each cell of the structure according to the desired frequency response of the filter (bandwidth, pass band ripple, location of transmission zeroes, etc). This methodology is also applicable to the design of filters with standard frequency responses (Chebyshev, Butterworth, etc). The theoretical work is also supported with experimental results of several prototypes with different bandwidths, from narrow band responses to ultra wide band filters.

All telecommunication systems, such as cellular mobile networks (cellphones), object-detection systems (radars), and navigation systems that include satellite positioning systems (GPS), base their functioning on radio wave radiation with pre-defined frequencies and thus require a microwave filter to select the most appropriate frequencies. Generally speaking, the more highly-selective a filter is, the less non-useful frequencies and interference it picks up. Recent advances in microwave instruments, semiconductors, fabrication technologies and microwave filters applications have ushered in a new era in performance but have also brought significant challenges, such as keeping fabrication costs low, miniaturizing, and making low-profile devices. These challenges must be met while at the same time maintaining the performance of conventional devices. The thesis proposes use of lossy filter concepts to maintain high quality filtering frequency response flatness and selectivity regardless of the filter’s physical size. The method is applied to lumped element filters. It introduces resistances to the physical structure of the filter and hence a certain amount of loss to the frequency response of the filter. The lossy filter synthesis is based on the coupling matrix mode. The thesis also proposes modifications to the traditional lossy filter design techniques, to improve the filter performance in the stopband.

All telecommunication systems, such as cellular mobile networks (cellphones), object-detection systems (radars), and navigation systems that include satellite positioning systems (GPS), base their functioning on radio wave radiation with pre-defined frequencies and thus require a microwave filter to select the most appropriate frequencies. Generally speaking, the more highly-selective a filter is, the less non-useful frequencies and interference it picks up. Recent advances in microwave instruments, semiconductors, fabrication technologies and microwave filters applications have ushered in a new era in performance but have also brought significant challenges, such as keeping fabrication costs low, miniaturizing, and making low-profile devices. These challenges must be met while at the same time maintaining the performance of conventional devices. The thesis proposes use of lossy filter concepts to maintain high quality filtering frequency response flatness and selectivity regardless of the filter’s physical size. The method is applied to lumped element filters. It introduces resistances to the physical structure of the filter and hence a certain amount of loss to the frequency response of the filter. The lossy filter synthesis is based on the coupling matrix mode. The thesis also proposes modifications to the traditional lossy filter design techniques, to improve the filter performance in the stopband.

Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2007. / Tentzeris, Manos, Committee Member ; Wollack, Edward, Committee Member ; Cressler, John, Committee Member ; Papapolymerou, Ioannis, Committee Chair ; Laskar, Joy, Committee Co-Chair ; Ayazi, Farrokh, Committee Member.

by Siu-Chung Chan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 98-100). / Abstract also in Chinese. / Chapter CHAPTER 1 --- INTRODUCTION --- p.3 / Chapter CHAPTER 2 --- BACKGROUND THEORY --- p.6 / Chapter 2.1 --- Passive LC Low-pass Filter --- p.6 / Chapter 2.1.1 --- Butterworth Low-pass Filter --- p.6 / Chapter 2.1.2 --- Chebyshev Low-pass Filter --- p.8 / Chapter 2.2 --- Low-pass to Band-pass Transformation --- p.10 / Chapter 2.2.1 --- Impedance Inverter --- p.12 / Chapter 2.2.2 --- Admittance Inverter --- p.14 / Chapter 2.3 --- Coupled Resonator Band-pass Filter --- p.15 / Chapter 2.4 --- Active Filter Techniques --- p.19 / Chapter 2.4.1 --- Actively-coupled Passive Resonators --- p.20 / Chapter 2.4.2 --- Negative Resistance for Q-enhancement --- p.21 / Chapter 2.4.3 --- Transversal & Recursive Filters --- p.22 / Chapter 2.4.4 --- Active Inductors --- p.24 / Chapter 2.5 --- Chapter Summary --- p.27 / Chapter CHAPTER 3 --- NEGATIVE RESISTANCE BASED ACTIVE FILTER --- p.28 / Chapter 3.1 --- Lossy Coupled-Resonator Band-pass Filter --- p.28 / Chapter 3.2 --- Negative Resistance Circuit --- p.32 / Chapter 3.2.1 --- Capacitive Feedback Configuration of CS MESFET --- p.33 / Chapter 3.2.2 --- Active LC-Resonator --- p.35 / Chapter 3.3 --- Design Criteria of Active Filter --- p.39 / Chapter 3.3.1 --- Choices of Feedback Capacitance --- p.40 / Chapter 3.3.2 --- Derivation of Design Requirements --- p.44 / Chapter 3.4 --- Chapter Summary --- p.46 / Chapter CHAPTER 4 --- INTERMODULATION ANALYSIS BY VOLTERRA-SERIES --- p.47 / Chapter 4.1 --- volterra-series analysis --- p.47 / Chapter 4.1.1 --- Nonlinear Transfer Functions --- p.48 / Chapter 4.1.2 --- Harmonic-Input Method --- p.50 / Chapter 4.2 --- Derivation of Intermodulation Products in Active Filter --- p.52 / Chapter 4.2.1 --- Modeling of Nonlinear MESFETs --- p.52 / Chapter 4.2.2 --- First Order Kernel --- p.56 / Chapter 4.2.3 --- Second Order Kernel --- p.58 / Chapter 4.2.4 --- Third Order Kernel --- p.61 / Chapter 4.3 --- Simplified Nonlinear Model of Active Filter --- p.66 / Chapter 4.4 --- Minimization of Intermodulation in Active Filter --- p.67 / Chapter 4.5 --- Chapter Summary --- p.73 / Chapter CHAPTER 5 --- DESIGN OF 900MHZ HYBRID ACTIVE FILTER --- p.74 / Chapter 5.1 --- Material Considerations --- p.74 / Chapter 5.1.1 --- Choice of MESFET --- p.75 / Chapter 5.1.2 --- Choice of Inductors --- p.75 / Chapter 5.1.3 --- Choice of Capacitors --- p.75 / Chapter 5.1.4 --- Choice of PCB Material --- p.76 / Chapter 5.2 --- Design of Hybrid Active Filters --- p.76 / Chapter 5.2.1 --- General Filter Structure --- p.76 / Chapter 5.2.2 --- Gate-Source & Feedback Capacitance Control --- p.78 / Chapter 5.2.3 --- Stability Issues --- p.79 / Chapter 5.2.4 --- PCB Layout --- p.82 / Chapter 5.2.5 --- Design Variants --- p.82 / Chapter 5.3 --- Measurements & Results --- p.84 / Chapter 5.3.1 --- Passive Filter Frequency Response Measurement --- p.85 / Chapter 5.3.2 --- Active Filter Frequency Response Measurement --- p.86 / Chapter 5.3.3 --- Two-Tone Intermodulation Measurement --- p.88 / Chapter 5.3.4 --- Gain-Compression Measurement --- p.92 / Chapter 5.4 --- Chapter Summary --- p.95 / Chapter CHAPTER 6 --- CONCLUSION --- p.96 / Chapter CHAPTER 7 --- FUTURE WORKS --- p.97 / REFERENCE --- p.98 / PUBLICATION LIST --- p.100 / APPENDIX --- p.101

Yim, Ho Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 125-128). / Abstracts in English and Chinese. / Abstract --- p.ii / 論文摘要 --- p.iv / Acknowledgement --- p.vi / Table of Content --- p.vii / List of Figures --- p.x / List of Tables --- p.xiv / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Filter --- p.3 / Chapter 1.2 --- Antenna --- p.4 / Chapter 1.3 --- Outline of the Thesis --- p.6 / Chapter Chapter 2 --- Basic Theories in Filter and Patch Antenna Design --- p.7 / Chapter 2.1 --- Microwave Filter Design --- p.7 / Chapter 2.1.1 --- Transfer Functions --- p.8 / Chapter 2.1.2 --- Lowpass Prototype Filters and Elements --- p.14 / Chapter 2.1.3 --- Filter Transformations --- p.18 / Chapter 2.1.4 --- Admittance Inverter --- p.21 / Chapter 2.2 --- Antenna Concepts --- p.23 / Chapter 2.2.1 --- Microstrip Antenna --- p.23 / Chapter 2.2.2 --- Patch Antenna Design --- p.24 / Chapter 2.2.3 --- Polarization --- p.28 / Chapter Chapter 3 --- Review of Conventional Dual-band Filter Designs --- p.33 / Chapter 3.1 --- Bandstop / bandpass Filters in a Cascade Connection --- p.33 / Chapter 3.2 --- Stepped Impedance Resonator --- p.34 / Chapter 3.3 --- Tunable Transmission Zero for Spurious Responses Suppression --- p.36 / Chapter 3.4 --- Comparison --- p.38 / Chapter Chapter 4 --- Novel Dual-band Filter Design with Equal Bandwidth --- p.39 / Chapter 4.1 --- Introduction --- p.39 / Chapter 4.2 --- Frequency Behavior of Shunt Stubs --- p.39 / Chapter 4.3 --- Dual-band Resonator with Paralleled Stubs --- p.42 / Chapter 4.4 --- Dual-band Admittance Inverter --- p.47 / Chapter 4.5 --- Dual-band Filter Realization --- p.51 / Chapter 4.5.1 --- Simulation Examples --- p.54 / Chapter 4.5.2 --- Comparison of Simulation results --- p.60 / Chapter 4.5.3 --- Experimental Results --- p.64 / Chapter Chapter 5 --- Novel Dual-band Filter Design with Unequal Bandwidth --- p.70 / Chapter 5.1 --- Introduction --- p.70 / Chapter 5.2 --- Dual-band Resonator using Step-Impedance Line --- p.70 / Chapter 5.3 --- Dual-band Admittance Inverter --- p.74 / Chapter 5.4 --- Dual-band Filter Realization --- p.75 / Chapter 5.4.1 --- Comparison of Simulation Results --- p.81 / Chapter 5.4.2 --- Experimental Results --- p.85 / Chapter Chapter 6 --- Review of Conventional CP Antenna Designs --- p.91 / Chapter 6.1 --- Degenerated Mode Patch --- p.91 / Chapter 6.2 --- CP Stacked Microstrip Patch Antenna Array --- p.92 / Chapter 6.3 --- Coplanar Waveguide-fed Slot Antenna --- p.93 / Chapter 6.4 --- Dual-band CP antenna fed by 2 different 90° hybrid couplers --- p.95 / Chapter Chapter 7 --- Novel New Dual-band CP Antenna Design --- p.96 / Chapter 7.1 --- Introduction --- p.96 / Chapter 7.2 --- Dual-band CP Patch Antenna --- p.96 / Chapter 7.2.1 --- Slotted Square Patch Antenna --- p.96 / Chapter 7.2.2 --- Slotted Cross Patch Antenna --- p.99 / Chapter 7.2.3 --- Simulation Results: Slotted Cross Patch Antenna --- p.101 / Chapter 7.3 --- Dual-band Quadrature Hybrid --- p.104 / Chapter 7.3.1 --- Simulation Results: Dual-band Hybrid Coupler --- p.107 / Chapter 7.4 --- Dual-band CP Antenna Realization --- p.113 / Chapter 7.4.1 --- Antenna Configuration --- p.113 / Chapter 7.4.2 --- Measurement Setup --- p.114 / Chapter 7.4.3 --- Experimental Results --- p.115 / Chapter Chapter 8 --- Conclusions and Recommendations for Future Work --- p.123 / Chapter 8.1 --- Filter --- p.123 / Chapter 8.2 --- Antenna --- p.123 / Chapter 8.3 --- Recommendations for future work --- p.124 / References --- p.125 / Author's Publications --- p.128 / Acronyms and Abbreviations --- p.129

by R.M. Fano and A.W. Lawson. / "June 28, 1946." / Includes bibliographical references. / Contract OEMsr-262.

There are a significant number of microwave applications, where improvement of such qualities as manufacturing costs, size, weight, power consumption, etc. have attracted much research interest. In order to meet these requirements, new technologies can be actively involved in fabrication of microwave components with improved characteristics. One such fabrication technology is called LIGA (a German acronym with an English translation of lithography, electroforming, and moulding) that allows fabrication of high aspect ratio (tall) structures, and only recently is receiving growing attention in microwave component fabrication.<p> The characteristics of high aspect ratio microstrip and coplanar waveguide (CPW) transmission lines are investigated in this thesis. Very low impedance high aspect ratio CPW transmission lines can be realized. A high aspect ratio microstrip folded half wavelength open loop resonator is introduced. Effective configurations for external and bypass gap coupling with open loop resonators are given. Filters with transmission zeros in the stopband, consisting of high aspect ratio single mode open loop resonators are presented to demonstrate the advantages of high aspect ratio structures in realizing lower external quality factors or tight coupling. The transmission zeros are created by novel coupling routings. Some of the filters are fabricated and the filter responses are measured to validate high aspect ratio coupling structures. High aspect ratio diplexers with increased channel isolation are also designed by appropriately combining filters with transmission zeros.<p> A wideband bandpass filter design method, based on the electromagnetic bandgap (EBG) concept is introduced in this thesis. The wideband filters are miniaturized as a result of using the EBG concept in design. An EBG based wideband filter consisting of unit cells that are realized by using high aspect ratio CPW stepped impedance resonators is also presented. The main advantage of this approach is that the high aspect ratio CPW structures make short unit cells practically realizable, resulting in compact filter structure.

There are a significant number of microwave applications, where improvement of such qualities as manufacturing costs, size, weight, power consumption, etc. have attracted much research interest. In order to meet these requirements, new technologies can be actively involved in fabrication of microwave components with improved characteristics. One such fabrication technology is called LIGA (a German acronym with an English translation of lithography, electroforming, and moulding) that allows fabrication of high aspect ratio (tall) structures, and only recently is receiving growing attention in microwave component fabrication.<p> The characteristics of high aspect ratio microstrip and coplanar waveguide (CPW) transmission lines are investigated in this thesis. Very low impedance high aspect ratio CPW transmission lines can be realized. A high aspect ratio microstrip folded half wavelength open loop resonator is introduced. Effective configurations for external and bypass gap coupling with open loop resonators are given. Filters with transmission zeros in the stopband, consisting of high aspect ratio single mode open loop resonators are presented to demonstrate the advantages of high aspect ratio structures in realizing lower external quality factors or tight coupling. The transmission zeros are created by novel coupling routings. Some of the filters are fabricated and the filter responses are measured to validate high aspect ratio coupling structures. High aspect ratio diplexers with increased channel isolation are also designed by appropriately combining filters with transmission zeros.<p> A wideband bandpass filter design method, based on the electromagnetic bandgap (EBG) concept is introduced in this thesis. The wideband filters are miniaturized as a result of using the EBG concept in design. An EBG based wideband filter consisting of unit cells that are realized by using high aspect ratio CPW stepped impedance resonators is also presented. The main advantage of this approach is that the high aspect ratio CPW structures make short unit cells practically realizable, resulting in compact filter structure.

Thesis (M.App.Sc.) - Carleton University, 2005. / Includes bibliographical references (p. 90-93). Also available in electronic format on the Internet.