An Extremely Miniaturized Microstrip Balun Filter

The field of RF (radio frequency) and microwave is rapidly growing because of its use in wireless communication systems. In wireless applications, baluns which frequently connect a bandpass filter with a balanced component are significant system factors but usually occupy much of the volume of the systems.Thus, with the speedy development of modern communication, reducing the size of balun is the main challenge in making RF systems compact. In addition, the poor balanced port matching and isolation performance of many conventional baluns limits their application. In this thesis, a novel enhanced balun bandpass filter for extremely miniaturization is demonstrated utilizing the combination of diagonally shorted coupled lines and parallel end shorted coupled lines both with shunt lumped capacitors. This method can largely reduce the required electrical length of transmission line, not only approximately maintaining the same characteristic around the center frequency but also effectively suppressing the spurious passband.Meanwhile, a resistive network between the outputs is presented to realize the balanced matching and isolation. Comparing with the typical Marchand Balun, it takes better performance as well as shows a wider upper stopband. Design equations and method is fully explained in this thesis. An extremely miniaturized balun filter operating at 1GHz of microstrip line form is fabricated on PCB substrate with 15 degree electrical length of the coupled lines. Both theoretical and measured performances are displayed. The experimental verification proves the usefulness of the proposed balun filter and its advantages of the application for mobile communications, etc.Contents ..................................................................................................................... I Nomenclature ............................................................................................................ II List of Tables ........................................................................................................... III List of Figures ......................................................................................................... III Abstract ..................................................................................................................... V CHAPTER 1 Introduction ......................................................................................... 1 1.1 Background and Introduction of Balun ........................................................ 1 1.2 Organization of the Thesis ........................................................................... 6 CHAPTER 2 Balun Filter Design Theory ................................................................ 7 2.1 Size Reduction Method ................................................................................ 7 2.1.1 Diagonally Shorted Coupled Lines with Lumped Capacitors ........... 8 2.1.2 Parallel End Shorted Coupled Lines with Lumped Capacitors......... 11 2.2 Ordinary Balun Design .............................................................................. 14 2.3 New Structure for Miniaturized Balun Filter ............................................. 16 2.4 Isolation and Matching Network of Balanced Outputs .............................. 19 CHAPTER 3 Simulation, Fabrication and Measurement ....................................... 23 3.1 Circuit Simulating by ADS and Analysis ................................................... 23 3.2 Full-Wave EM Simulation by HFSS and Optimization ............................. 28 3.3 Fabrication and Measurement .................................................................... 32 Chapter 4 Conclusion .............................................................................................. 39 References ............................................................................................................... 40 Acknowledgement .................................................................................................. 4

Ultra-Wideband Phased Arrays for Small Mobile Platforms

This dissertation presents the development of a new class of Ultra-Wideband (UWB) apertures for aerial applications by introducing designs with over 50:1 bandwidth and novel differential feeding approaches. Designs that enable vertical integration for flip-chip millimeter-wave (UWB) transceivers are presented for small aerial platforms. Specifically, a new scalable tightly coupled array is introduced with differential feeding for chip integration. This new class of beam-forming arrays are fabricated and experimentally tested for validation with operation from as low as 130 MHz up to 18 GHz. A major achievement is the study of millimeter wave beamforming designs that operate from 22-80 GHz, fabricated using low-cost printed circuit board (PCB) methods. This low-cost fabrication approach and associated testing of the beamforming arrays are unique and game-changing

Dual-band Microwave Components And Their Applications

In general, Dual-Band technology enables microwave components to work at two different frequencies. This thesis introduces novel dual-band microwave components and their applications. Chapter 2 presents a novel compact dual-band balun (converting unbalanced signals to balanced ones). The ratio between two working frequencies is analyzed. A novel compact microstrip crossover (letting two lines to cross each other with very high isolation) and its dual-band application is the subject of chapter 3. A dual-frequency cloak based on lumped LC-circuits is introduced in chapter 4. In chapter 5, a dual-band RF device to detect dielectric constant changes of liquids in polydimethylsiloxane (PDMS) microfluidic channels has been presented. Such a device is very sensitive, and it has significantly improved the stability. Finally, conclusion of this thesis and future works are given in chapter 6

Compact Metamaterials Induced Circuits and Functional Devices

In recent years, we have witnessed a rapid expansion of using metamaterials to manipulate light or electromagnetic (EM) wave in a subwavelength scale. Specially, metamaterials have a strict limitation on element dimension from effective medium theory with respect to photonic crystals and other planar structures such as frequency selective surface (FSS). In this chapter, we review our effort in exploring physics and working mechanisms for element miniaturization along with the resulting effects on element EM response. Based on these results, we afford some guidelines on how to design and employ these compact meta-atoms in engineering functional devices with high performances. We found that some specific types of planar fractal or meandered structures are particularly suitable to achieve element miniaturization. In what follows, we review our effort in Section 1 to explore novel theory and hybrid method in designing broadband and dual band planar devices. By using single or double such compact composite right-/left-handed (CRLH) atom, we show that many microwave/RF circuits, i.e., balun, rat-race coupler, power divider and diplexer, can be further reduced while without inducing much transmission loss from two perspectives of lumped and distributed CRLH TLs. In Section 2, we show that a more compact LH atom can be engineered by combining a fractal ring and a meandered thin line. Numerical and experimental results demonstrate that a subwavelength focusing is achieved in terms of smooth outgoing field and higher imaging resolution. Section 3 is devoted to a clocking device from the new concept of superscatterer illusions. To realize the required material parameters, we propose a new mechanism by combining both electric and magnetic particles in a composite meta-atom. Such deep subwavelength particles enable exact manipulation of material parameters and thus facilitate desirable illusion performances of a proof-of-concept sample constructed by 6408 gradually varying meta-atoms. Finally, we summarize our results in the last section

2008 Index IEEE Transactions on Control Systems Technology Vol. 16

This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author\u27s name. The primary entry includes the coauthors\u27 names, the title of the paper or other item, and its location, specified by the publication abbreviation, year, month, and inclusive pagination. The Subject Index contains entries describing the item under all appropriate subject headings, plus the first author\u27s name, the publication abbreviation, month, and year, and inclusive pages. Note that the item title is found only under the primary entry in the Author Index

2009 Index IEEE Antennas and Wireless Propagation Letters Vol. 8

This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author\u27s name. The primary entry includes the coauthors\u27 names, the title of the paper or other item, and its location, specified by the publication abbreviation, year, month, and inclusive pagination. The Subject Index contains entries describing the item under all appropriate subject headings, plus the first author\u27s name, the publication abbreviation, month, and year, and inclusive pages. Note that the item title is found only under the primary entry in the Author Index

MMIC mixers

Ankara : Department of Electrical and Electronics Engineering and Institute of Engineering and Sciences, Bilkent University, 1996.Thesis (Master's) -- Bilkent University, 1996.Includes bibliographical references leaves 96-99.New ways of achieving broadband, low-cost, reliable mixers are investigated. Resistive MESFET mixer topology is the main focus of this work. Despite the accurate modeling difficulties of resistive mode operation, promising results are obtained. Three resistive MESFET mixers and one double balanced mixer with a diode quad are designed in the frequency range of 10GHz-20GHz. A new passive balım which can be fabricated using a standard MMIC process is proposed. The all-passive floating FET mixer and its improved version, both of which include the new balun, demonstrate good port isolation and conversion gains at low local oscillator power levels, in very small area. Additionally, a new single balanced mixer topology employing resistive mode MESFETs is presented. The chips are designed using Microwave Harmonica, layouts are generated using CADENCE microwave design enviroment and the chips are fabricated by CEC-Marconi’s 0.5 fim GaAs (F20) process.Özgür, MehmetM.S