Microwave Engineering Europe - July/August 2008 - (Page 10)

10 COVER FEATURE — EM SIMULATION Effective EM simulations with micro−λ resolution in macro-λ objects — General Huygens Box implementation By the SEMCAD X Team, Schmid & Partner Engineering AG, Zurich, Switzerland I. Introduction: Advantages of interfacing raytracing - MoM - FDTD - FEM - QED methods A wide range of powerful electromagnetic simulation tools are available today that are based on different methods of computational electromagnetics developed over the past four decades. Each of these software packages can simulate real world problems of large complexity but is limited to a certain problem category, i.e., relatively small ranges of spatial dimensions in terms of wavelength. Examples are wave propagation in cities (Ray-Tracing), electrically large antennas and scatterers (MoM), mobile phone mounted on the body (FDTD), micro-devices implanted inside the body or structures on semi-conductors (FEM) to molecular conformational changes within biological systems (QED). For example, FDTD is well-suited for problem of spatial dimensions between 0.01 to 10 wavelengths whereas the computational effort scales with the power of 4 (time step x number of cells) and the memory requirements with the power of 3 with respect to spatial reﬁnements. Many of today’s engineering problems for analysis and optimization have difﬁculty crossing these spatial dimensions. Examples include: • Determination of MIMO performance in a speciﬁc multipath environment; • Passive or optical devices embedded in larger structures; • EMI on multichip levels; • Assessment of the heating or interference potential of implanted micro devices exposed in MRI machines or workplace exposures; • Tissue damage modeling in EM cancer treatment modalities; • Investigation of electroporation effects that are externally induced; etc. The limitations of the available tools are evident when addressing these obstacles. Until now, the only way to cross Figure 1: Huygens source: the red box acts as a Huygens source surface, i.e., the incident ﬁeld calculated on the left is used as the excitation. In this example, four Huygens simulations are nested (base station, urban environment, human body and mobile phone in the right hand). multiple spatial dimensions was to either introduce simpliﬁcations or to increase the computational space by compromising the spatial resolution. Both approaches though can potentially introduce unknown and unwanted uncertainties into the solutions or exceed the capabilities of supercomputers. Hybrid approaches were also deemed promising but they are not sufﬁciently userfriendly. SPEAG in cooperation with the IT’IS Foundation has developed a novel, user-friendly, straightforward technique to effectively overcome these limitations. Since all solvers operate on the same non-homogenous rectangular grid, the same high-end graphical user interface SEMCAD X can be used regardless of the solver [2]. The solvers include the full wave solvers C-FDTD, C-ADI-FDTD, the new family of QS solvers and a thermal solver. The developed novel total-ﬁeld/scatteredﬁeld interface, that is referred to as the General Huygens Box interface and is described below, enables straightforward coupling between the solvers, i.e., spatial or physical dimensions. It also provides a simple open interface for coupling with other custom-made or commercial solvers. In addition, we are collaborating with various companies to provide user-friendly interfaces for different software packages. II. Methods SEMCAD X [2] is a universal simulation platform with a high-end graphical user interface that integrates various solvers such as SEMCAD FW (family of full-wave EM solvers such as C-FDTD, C-ADIFDTD, etc.), SEMCAD QS (family of Finite Element (FEM) based low frequency and static solvers), SEMCAD Tº (thermal solvers for thin conductors, vessels trees, etc.), SEMCAD POP (human models representing the human population), and SEMCAD Spice (couples full-wave analysis with circuit simulators). By combining SEMCAD X with Acceleware’s high performance platform ClusterInABox [1], Microwave Engineering Europe ● July/August 2008 ● www.mwee.com http://www.mwee.com

Table of Contents Feed for the Digital Edition of Microwave Engineering Europe - July/August 2008

Microwave Engineering Europe - July/August 2008 Contents News Comment Cover Feature: Effective EM Simulations with Micro−λ Resolution in Macro-λ Objects — General Huygens Box Implementation RF CMOS: Programmable Transceiver IC Minimises OEM Inventory for Femtocells CAD/EDA: Software-Defined Radio Platforms CAD/EDA: Cadence Enhances RF Verification While AWR Delivers an Improved Microwave Office How to Meet the Design Challenges of WiMAX Power Amplifiers Products Calendar

Microwave Engineering Europe - July/August 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.