Heterogeneous Integration of RF and Microwave Systems Using Multi-layer Low-Temperature Co-fired Ceramics Technology

[eng] The aim of this work is the development of a modelling methodology for the fast analysis of non-radiative multilayer RF passive components without compromising solution accuracy. Instead of following a compact model approach, oftenly used in integrated technologies, the method is based on a specialized quasi-static partial element equivalent circuit (PEEC) numerical solver. Besides speed and accuracy, the solver can be embedded in circuit simulators; thus, models are already available in the schematic entry. Using this framework, model scalability is enhanced in terms of geometry, substrate cross-section, material properties, topology and boundary conditions. The dissertation starts showing the actual performance of the obtained solver and the motivations beneath its development. Then, the description about solver development is splitted in three parts, but all of them are interrelated. First, the PEEC formulation is adapted according to relevant electromagnetic behaviour of the component. It is worth stressing that a different perspective related to the principle of virtual work is used in this formulation. The second part deals with the evaluation of partial elements, the core of the solver. It is carried out using analytical space-domain close-form solutions of the Green’s function (GF) of the substrate. Partial elements are then assembled into a mesh. Therefore, the importance of the mesh up on solution accuracy is discussed in the last part and a basic layout aware mesh generator is proposed. Practical application of the methodology includes the implementation of a library of RF passives for multilayer substrate. For validation, the chosen substrate is a low temperature co-fired ceramics (LTCC) technology. Different set of devices have been fabricated, characterized and compared against model prediction. In addition, the obtained results are also verified using state-of-the-art electromagnetic solvers.[spa] El objetivo de este trabajo es el desarrollo de una metodología de modelado para el análisis rápido, pero sin comprometer la precisión de la solución, de componentes pasivos no radiativos de RF en substratos multicapa. El método se basa en el algoritmo numérico cuasi-estático de los elementos parciales de circuito equivalente (PEEC). Éste puede ser incorporado en simuladores de circuitos; por tanto, los modelos ya están disponibles en la entrada de esquemático de forma transparente para el diseñador de circuitos. Utilizando este marco, la escalabilidad del modelo se mejora en términos de la geometría, la definición del corte tecnológico, las propiedades del material, la topología del componente y las condiciones de contorno electro-magnéticas. Esta disertación comienza mostrando las motivaciones que han llevado a su desarrollo y la capacidad real del método de resolución obtenido. A partir de aquí, se realiza la descripción de todo el desarrollo del marco numérico que se divide en tres partes que están interrelacionadas. En primer lugar, la formulación PEEC se adapta según el comportamiento electromagnético real del componente. Vale la pena subrayar que en esta formulación se utiliza una perspectiva diferente a la habitual y que está relacionada con el principio de los trabajos virtuales de d’Alembert. La segunda parte trata de cómo se evalúan los elementos parciales y constituye el núcleo principal del algoritmo. Se lleva a cabo utilizando soluciones analíticas de la función de Green (GF) del sustrato en el dominio espacial. Los elementos parciales, que forman la malla numérica del modelo, se ensamblan en la matriz del sistema siguiendo un procedimiento de análisis nodal modificado (MNA). En la última parte, se discute la importancia de la malla sobre la precisión de la solución y se propone un generador de malla basado en la física del componente y no sólo en la descripción de la geometría. Como aplicación práctica de la metodología, se realiza la generación de una biblioteca de componentes pasivos RF para sustratos multicapa

Application of HPC in eddy current electromagnetic problem solution

As engineering problems are becoming more and more advanced, the size of an average model solved by partial differential equations is rapidly growing and, in order to keep simulation times within reasonable bounds, both faster computers and more efficient software implementations are needed. In the first part of this thesis, the full potential of simulation software has been exploited through high performance parallel computing techniques. In particular, the simulation of induction heating processes is accomplished within reasonable solution times, by implementing different parallel direct solvers for large sparse linear system, in the solution process of a commercial software. The performance of such library on shared memory systems has been remarkably improved by implementing a multithreaded version of MUMPS (MUltifrontal Massively Parallel Solver) library, which have been tested on benchmark matrices arising from typical induction heating process simulations. A new multithreading approach and a low rank approximation technique have been implemented and developed by MUMPS team in Lyon and Toulouse. In the context of a collaboration between MUMPS team and DII-University of Padova, a preliminary version of such functionalities could be tested on induction heating benchmark problems, and a substantial reduction of the computational cost and memory requirements could be achieved. In the second part of this thesis, some examples of design methodology by virtual prototyping have been described. Complex multiphysics simulations involving electromagnetic, circuital, thermal and mechanical problems have been performed by exploiting parallel solvers, as developed in the first part of this thesis. Finally, multiobjective stochastic optimization algorithms have been applied to multiphysics 3D model simulations in search of a set of improved induction heating device configurations

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

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

Constraint-Aware, Scalable, and Efficient Algorithms for Multi-Chip Power Module Layout Optimization

Moving towards an electrified world requires ultra high-density power converters. Electric vehicles, electrified aerospace, data centers, etc. are just a few fields among wide application areas of power electronic systems, where high-density power converters are essential. As a critical part of these power converters, power semiconductor modules and their layout optimization has been identified as a crucial step in achieving the maximum performance and density for wide bandgap technologies (i.e., GaN and SiC). New packaging technologies are also introduced to produce reliable and efficient multichip power module (MCPM) designs to push the current limits. The complexity of the emerging MCPM layouts is surpassing the capability of a manual, iterative design process to produce an optimum design with agile development requirements. An electronic design automation tool called PowerSynth has been introduced with ongoing research toward enhanced capabilities to speed up the optimized MCPM layout design process. This dissertation presents the PowerSynth progression timeline with the methodology updates and corresponding critical results compared to v1.1. The first released version (v1.1) of PowerSynth demonstrated the benefits of layout abstraction, and reduced-order modeling techniques to perform rapid optimization of the MCPM module compared to the traditional, manual, and iterative design approach. However, that version is limited by several key factors: layout representation technique, layout generation algorithms, iterative design-rule-checking (DRC), optimization algorithm candidates, etc. To address these limitations, and enhance PowerSynth’s capabilities, constraint-aware, scalable, and efficient algorithms have been developed and implemented. PowerSynth layout engine has evolved from v1.3 to v2.0 throughout the last five years to incorporate the algorithm updates and generate all 2D/2.5D/3D Manhattan layout solutions. These fundamental changes in the layout generation methodology have also called for updates in the performance modeling techniques and enabled exploring different optimization algorithms. The latest PowerSynth 2 architecture has been implemented to enable electro-thermo-mechanical and reliability optimization on 2D/2.5D/3D MCPM layouts, and set up a path toward cabinet-level optimization. PowerSynth v2.0 computer-aided design (CAD) flow has been hardware-validated through manufacturing and testing of an optimized novel 3D MCPM layout. The flow has shown significant speedup compared to the manual design flow with a comparable optimization result

Numerical and Analytical Methods in Electromagnetics

Like all branches of physics and engineering, electromagnetics relies on mathematical methods for modeling, simulation, and design procedures in all of its aspects (radiation, propagation, scattering, imaging, etc.). Originally, rigorous analytical techniques were the only machinery available to produce any useful results. In the 1960s and 1970s, emphasis was placed on asymptotic techniques, which produced approximations of the fields for very high frequencies when closed-form solutions were not feasible. Later, when computers demonstrated explosive progress, numerical techniques were utilized to develop approximate results of controllable accuracy for arbitrary geometries. In this Special Issue, the most recent advances in the aforementioned approaches are presented to illustrate the state-of-the-art mathematical techniques in electromagnetics

Simulation Tools and Developments on Integral Formulations for the Computation of Eddy Currents

openComputational electromagnetics is a discipline that since many years ago has permitted deep innovations in the study of electromagnetic problems. Even if, nowadays, commercial softwares undeniably show a certain maturity when applied to practical problems, some research work has still to be done in going beyond the theoretical limits underneath the various approaches. With respect to this, integral formulations still present some open issues. Historically, the exploitation of these formulations to study eddy currents started around the 90s with the seminal works of G. Albanese, R. Martone and R. Rubinacci together with the research activity of L. Kettunen and L. R. Turner and then with G. Meunier, who more recently rediscovered them. Lately, the contributions of L. Codecasa, R. Specogna and F. Trevisan have further increased the possibilities offered by this approach by introducing a set of new shape functions for polyhedral grids that are based on a discrete geometrical reinterpretation of the physics of electromagnetic phenomena. One of the main features characterizing integral formulations to compute eddy currents stems from the fact that they do not require any discretization of the complement of the conductor to be studied. As a drawback, they lead to fully populated matrices whose assembly results to be remarkably time consuming and whose size can sometimes saturate the memory of the calculator. In this respect, this composition presents a new volume integral code for polyhedral grids describing how a fast and efficient cohomology computation can be implemented to treat also non-simply connected domains. Then, some tools are provided for the reduction of the size, and thus of the assembly time too, of the fully populated matrix. More precisely, the attention is focused on the exploitation of cyclic symmetry and on the novel topology-related issues arising when integral formulations have to be referred only to the symmetry cell of the complete conducting domain in order not to spoil the block-circulant property of the system matrix when building the cohomology generators or the gauging tree. Furthermore, also new iterative methods are considered as additional approaches to limit the size of the system matrix to be assembled: despite being already known to the computational electromagnetics community, their convergence behaviour has not been studied yet when they are applied to integral formulations as the one here proposed. Specifically, after presenting a purely iterative scheme derived from the volume integral formulation whose convergence can be somehow problematic, we propose a new direct-iterative method based on Krylov subspace techniques and on the domain splitting into multiple conductors that exhibits a much improved behaviour. The study of these methods leads to new interesting findings to be considered in addition to matrix compression techniques.Dottorato di ricerca in Ingegneria industriale e dell'informazioneopenPassarotto, Maur

Modelling and analysis of crosstalk in scaled CMOS interconnects

The development of a general coupled RLC interconnect model for simulating scaled bus structures m VLSI is presented. Several different methods for extracting submicron resistance, inductance and capacitance parameters are documented. Realistic scaling dimensions for deep submicron design rules are derived and used within the model. Deep submicron HSPICE device models are derived through the use of constant-voltage scaling theory on existing 0.75µm and 1.0µm models to create accurate interconnect bus drivers. This complete model is then used to analyse crosstalk noise and delay effects on multiple scaling levels to determine the dependence of crosstalk on scaling level. Using this data, layout techniques and processing methods are suggested to reduce crosstalk in system

Recent Topics in Electromagnetic Compatibility

Recent Topics in Electromagnetic Compatability discusses several topics in electromagnetic compatibility (EMC) and electromagnetic interference (EMI), including measurements, shielding, emission, interference, biomedical devices, and numerical modeling. Over five sections, chapters address the electromagnetic spectrum of corona discharge, life cycle assessment of flexible electromagnetic shields, EMC requirements for implantable medical devices, analysis and design of absorbers for EMC applications, artificial surfaces, and media for EMC and EMI shielding, and much more