189 research outputs found

    Segmentation strategy for the efficient analysis and design of substrate integrated waveguide directly coupled cavity filters

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    This paper is a postprint of a paper submitted to and accepted for publication in IET Microwaves Antennas and Propagation and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at IET Digital LibraryIn this study, a new segmentation strategy is presented for the full-wave analysis of directly coupled cavity filters in substrate integrated waveguide (SIW) technology. The whole SIW filter is enclosed inside an external fictitious rectangular waveguide, which does not affect the propagation inside the SIW assuming that the SIW is well designed and there is no significant power leakage. The external rectangular waveguide allows to easily segment the structure into building blocks that are composed of circular metallic vias inside a rectangular waveguide. The generalised scattering matrix of these building blocks is obtained with highly efficient techniques specifically suited for the analysis of H-plane rectangular waveguide devices. Some building blocks are repeated along the structure, and their scattering matrix has to be computed only once. The scattering matrices of all the building blocks are cascaded and the scattering matrix of the whole filter is obtained. A SIW filter of eight coupled cavities with a bandpass response centred at 11 GHz is analysed. Results from this analysis show that the computational time has been significantly reduced when compared with other specific SIW analysis methods or with commercial general purpose software, while maintaining a good accuracy.This work was funded by the Ministerio de Economia y Competitividad of the Spanish Government under the project number TEC2013-47037-C5-1-R.Martínez-Zamora, JÁ.; Belenguer, Á.; Esteban González, H.; Boria Esbert, VE. (2016). Segmentation strategy for the efficient analysis and design of substrate integrated waveguide directly coupled cavity filters. IET Microwaves Antennas and Propagation. 10(3):283-287. https://doi.org/10.1049/iet-map.2015.0284S28328710

    Advanced Electromagnetic Numerical Modeling Techniques for Various Periodic and Quasi-Periodic Systems

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    This dissertation is mainly concerned with several advanced electromagnetic modeling techniques for practical complex systems, which involve periodic analyses. The focus is to reveal the physics of the electromagnetic wave interaction with the complex structures, and also to arrive at improved computational algorithms. This dissertation consists of three self-contained parts, each discussing one modeling technique. Examples presented in this dissertation include (a) an analysis of conductor surface-roughness effects, (b) a novel model for vertical interconnects (vias) and (c) a leaky-wave study of a Fabry-Perot resonant cavity antenna. The first part investigates conductor surface roughness effects for stripline. An equivalent rough-surface-impedance is extracted using a periodic full-wave analysis and is then used for the modification of the transmission line per-unit-length parameter. The second part proposes a semi-analytical analysis for massively-coupled vias with arbitrarily-shaped antipads, based on the reciprocity theorem. The use of reciprocity yields simple design formulas and is seen to greatly improve the computational efficiency, due to the fast-converging mode-matching calculation. The third part presents a leaky-wave study of a Fabry-Perot cavity antenna made from a patch array. The patch current densities are calculated using the array scanning method. Based on this, a "leaky-wave current" is defined and calculated using residue integration. In addition, the radiation properties of a large finite-size array (truncation effects) are evaluated. All three proposed models are verified by full-wave simulations and/or measurements. Numerical results prove the effectiveness and accuracy of these models.Electrical and Computer Engineering, Department o

    Modeling multi-layer via structure using PEEC method

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    In this dissertation, a new integral equation formulation for via structures is developed for the capacitance extraction between vias and planes. The proposed method can be used to calculate the shared-antipad via structure which is widely used in highspeed differential signal interconnects. In addition, we use the image theory to handle inhomogeneous media. Further, a new technique is given to reduce computational resources for via-to-plane structures based on properties of the matrix coefficient. The extracted capacitance is also incorporated into the physics-based circuit model to characterize the overall performance of the via transition. In the second paper, a rigorous modeling of the shared-antipad via structure is developed using surface partial element equivalent circuit (PEEC). The cavity Green\u27s function is used to evaluate the equivalent circuit elements, thereby requiring fewer cells for numerical computation. The non-orthogonal, quadrilateral cell is used in the mesh to better accommodate the non-rectangular shape of the via and the antipad. A novel wave port excitation method is applied to the equivalent circuit to obtain the network parameters of the via transition. The Z-parameters of the via structure are calculated using the proposed method, and the results are validated with the finite element solution obtained from commercial software. In the third paper, an effective methodology is proposed to estimate the RF interference received by an antenna due to near-field coupling using divide-and-conquer based on reciprocity. The proposed methodology fits well with engineering practice, and is particularly suitable for pre-layout wireless system design and planning --Abstract, page iv

    New quasi-TEM waveguides using artificial surfaces and their application to antennas and circuits

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    Research interest: In recent years we have seen the emergence of commercial applications at high frequencies, such as the top part of the microwave band and the millimeter and sub-millimeter bands, and it is expected a big increase in the coming years. This growing demand requires a rapid development of low-cost technology with good performance at these frequencies, where common technologies, such as microstrip and standard waveguides, have some shortcomings. In particular, existing solutions for high-gain planar scanning antennas at these frequencies su er from the disadvantages of these technologies giving rise to high-cost products not suitable for high volume production. Objectives: The main objective of this thesis is to study the feasibility of a new proposal to improve existing solutions to date for low-cost high-gain planar scanning antennas at high frequencies. This overall objective has resulted in another central objective of this thesis, which is the research of new quasi-TEM waveguides that are more appropriate than current technologies for the realization of circuits and components at these frequency bands. These guided solutions make use of periodic or arti cial surfaces in order to con- ne and channel the elds within these waveguides. Methodology: The work follows a logical sequence of speci c tasks aimed at achieving the main objective of this thesis. Chapter 2 presents the proposed guiding solution and shows its performance numerical and experimentally. The optimized design of high-gain antennas based on waveguide slot arrays requires the development of e cient ad-hoc codes. The implementation and validation of this code is presented in Chapter 3, where a new method for the analysis of corrugated surfaces is proposed, and in Chapter 4, which extends this code to the analysis of waveguide slot arrays. The process design and optimization of a two-dimensional array is described in Chapter 5, where a preliminary experimental validation is also described. Moreover, the proposed guiding solution has inspired the development of a new guiding technology of wider bandwidth and more versatile for the realization of circuits and components at high frequencies. Chapter 6 presents the contributions to the study of this technology and its application to the design of circuits.Alfonso Alós, E. (2011). New quasi-TEM waveguides using artificial surfaces and their application to antennas and circuits [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/11073Palanci

    Electromagnetic Wave Theory and Applications

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    Contains reports on eleven research projects.Joint Services Electronics Program (Contract DAAG29-83-K-0003)Joint Services Electronics Program (Contract DAAL03-86-K-0002)National Science Foundation (Grant ECS82-03390)National Science Foundation (Grant ECS85-04381)Schlumberger-Doll Research CenterNational Aeronautics and Space Administration (Contract NAG 5-141)National Aeronautics and Space Administration (Contract NAS 5-26861)National Aeronautics and Space Administration (Contract NAG 5-270)U.S. Navy - Office of Naval Research (Contract N00014-83-K-0258)National Aeronautics and Space Administration (Contract NAG 5-725)International Business Machines, Inc.Lincoln Laborator

    Electromagnetic analysis of 2.5D structures in open layered media

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    This thesis presents a specialization of the integral equation (IE) method for the analysis of three-dimensional metallic and dielectric structures embedded in laterally unbounded (open) layered media. The method remains basically spatial but makes use of extensive analytical treatment of the vertical dependence of the problem in the 2D Fourier-transformed domain. The analytical treatment restricts somewhat the class of structures that can be analyzed. Still, the field of applicability remains very large, and includes most printed circuit and integrated circuit structures. The method is developed in full numerical detail, from first principles down to the properties of new Green's functions and the computation of particular types of convolution integrals. We show how the memory and time complexity are considerably reduced when compared to the requirements of the analysis of general 3D structures. With the newly developed tool, it is possible to deal with some peculiar characteristics of microwave and millimeter-wave circuits and antennas. Most noteworthy among these is the presence of thick metallizations (either electrically, or relative to circuit features). A novel full-wave analysis of arbitrarily shaped apertures in thick metallic screens is presented. This is compared to other methods, both full-wave and approximate, and demonstrated to offer excellent accuracy. Comparison with measured data, obtained from specially constructed prototypes, further validates the new technique. A second application is to the analysis of airbridges in coplanar waveguide (CPW) and slotline (SL) circuits. Comparison of measured and simulated data validates again our technique and provides valuable information about the behavior of CPW-fed slot loop antennas. Among the more specific applications, particular attention is devoted to the analysis and design of submillimeter-wave integrated dielectric lens feeds. These were object of study in the frame of a European Space Agency project, Integrated Front-End Receivers (IFER), which our Laboratory carried out in cooperation with a team at University of Toronto. The analysis method developed in this work encompasses and extends all previous work done at our Laboratory (LEMA) related with the analysis of this kind of feed. Together with the advanced 3D ray-tracing code developed at University of Toronto, it is possible to gain a high degree of insight into the behavior of these integrated receivers

    Modeling EMI Resulting from a Signal Via Transition Through Power/Ground Layers

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    Signal transitioning through layers on vias are very common in multi-layer printed circuit board (PCB) design. For a signal via transitioning through the internal power and ground planes, the return current must switch from one reference plane to another reference plane. The discontinuity of the return current at the via excites the power and ground planes, and results in noise on the power bus that can lead to signal integrity, as well as EMI problems. Numerical methods, such as the finite-difference time-domain (FDTD), Moment of Methods (MoM), and partial element equivalent circuit (PEEC) method, were employed herein to study this problem. The modeled results are supported by measurements. In addition, a common EMI mitigation approach of adding a decoupling capacitor was investigated with the FDTD method

    Passive Microwave Components and Antennas

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    Hybrid integration of synthesized dielectric image waveguides in substrate integrated circuit technology and its millimeter wave applications

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    Analysis, design, and fabrication of the SIIG -- Mode excitation in the SIIG -- Integrated dielectric antennas -- SIIG bends and power splitting/combining -- The SIIG in the context of substrate integrated circuits
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