Partial Element Equivalent Circuit Method For Three-Dimensional Fullmedium Systems And Its Modeling

In the future, mobile communication terminals will be smaller, lighter, cheaper,and consume less power. All these new features require that IC technology couldintegrate digital circuits, fundamental frequency circuits, intermediate frequencycircuits, and radio frequency circuits into a single chip. Silicon-based CMOS seemsthe only possible technology to realize this System-on-Chip process. However, aproblem arises with the silicon-based RF IC: the ohmic losses of passive devices areexcessively high. With the rapid progress in CMOS micron/submicron technology,this obstacle is receiving more and more efforts from microelectronic engineers andscientists. How to analyze the electromagnetic characteristic of on-chip passivecomponents with rapidity and accuracy is critical in resolving the problem. Whereasin micron/submicron dimension, silicon-based passive devices exhibit a series ofnovel characteristics, which invalidate classic circuit theory and render 3-D full-wavefield analysis impractical.Partial element equivalent circuit (PEEC) method is a full-wave equivalentcircuit approach, which can model arbitrary 3-D multi-conductor systems perfectly.By regarding dielectrics as free-space containing polarization charges and currents,this approach can be extended to model geometries including dielectrics. Theequivalent circuit model would contain a new kind of circuit element called excesscapacitor, which represents the polarization effects in dielectrics. PEEC model doesnot take magnetic medium into consideration and therefore is not complete;however,as we know, a promising solution for the problem would be to introduce RF magneticmedium into on-chip passive devices. This necessitates a fast and accurate simulationtechnique for magnetic medium in RF IC development.This dissertation generalizes the PEEC model into a fullmedium PEEC modelwhich can deal with the full medium systems. This full-wave equivalent circuit modelis quantitative in describing the magnetization and polarization. Based on generalizedform of the Maxwell's Equations, this dissertation first equals the simple medium tofree space with bound sources by rigid mathematic deduction so that all boundsources including magnetization currents, polarization charges and polarizationcurrents can explicitly appear in the electromagnetic mathematic model;then,distribution area and existence form of all kinds of bound sources in homogeneoussimple medium is determined, and free-space equivalence means that the Green'sfunction and the retarded potential needed for the solution of the D'Alembertequations are quantities in free space. The conductive, electric and magnetic mediumsare all treated as the same role (i.e. source space) in the circuit model. Thus thefullmedia PEEC model can be established after creating numeric meshes in the sourceregion, and novel excess circuit elements, including magnetization excess capacitance,magnetization excess resistance and the coefficient of current-controlled surfaceconductive current source are derived in the generalized PEEC model. With adequatesimplification and reasonable approximation, this model solves all kinds ofelectromagnetic couplings involved in on-chip spiral inductors, such as skin andproximity effect in conductor, lossy substrate coupling, and enhancement effects ofmagnetic matter.