Microwave Engineering Europe - July/August 2008 - (Page 11)

COVER FEATURE — EM SIMULATION 11 simulations can be performed up to ﬁfty times faster than with other currently available tools. Although our revolutionary tools introduced unparalleled speeds of over a billion cells per second, there is still a growing demand to solve even larger problems that require crossing the fundamental dimensional boundaries as described above. Thus, SPEAG developed a novel, user-friendly generalized interface, the Generalized Huygens Box that effectively couples different solvers without accelerating error propagation. It is based on the concepts of the Huygens Box [3], a generalized Total-Field Scattered-Field (TFSF) plane wave excitation, and the Block Iterative Technique [4], which solves weakly coupled problems effectively. The vast majority of problems when crossing the spatial dimensions can be divided into weakly coupled subregions. The application is intuitive and straightforward: i) dimension 1 (D1) primary (Index = 1) simulation (D11, D20): A simulation of a source region to determine the incident ﬁeld distribution on the Huygens box region of subdimension 2. Typically characterized by coarse mesh and a large time step and, therefore, short simulation times. Different simulations can be conducted to determine the worst-case incident excitation for subdimension 2. The solvers best suited for these computations are used. ii) subdimension 2 primary simulation (D11, D21): The results of the dimension 1 simulation are used as the excitation source of the Huygens box as deﬁned in subdimension 2 (if nested, the computation of the Huygens box region of subsubdimension 3). Typically characterized by ﬁne mesh resolution and a small time step, a small overall mesh size results in average simulation times. Different conﬁgurations for the above excitation can be studied effectively, i.e., different lead paths. Again the solvers most suitable for this excitation can be used. iii) dimension 1 secondary w/ backward solution to consider the effect of backscattering on the solution (D12, D21): The ﬁeld in the scattered area of the Huygens simulation is delivered back to the previous spatial dimension simulation using the ‘inversed’ Huygens box source. iv) subdimension 2 secondary simulation (D12, D22): A simulation of a source Figure 2: Using the Huygens source approach, the exact mode is excited without increasing the length or artiﬁcially adding FDTD cells to establish the mode in this optical waveguide. In addition, the source/excitation information can be delivered to the waveguide regardless of the external method or tool used. This opens the numerical boundaries for the analysis of much more complex optical devices. Figure 3: This example demonstrates the empowering functionality of the novel Generalized Huygens Box for cross-platform and cross-method computations. The base station antenna is computed by FEKO, EMSS, whereas SEMCAD X, SPEAG was used for the interactions with the human body exposed at a larger distance from the antenna. The effect of different anatomies and postures was computed without recomputing the incident ﬁelds, thereby signiﬁcantly increasing the effectiveness and reducing the related errors and uncertainties. Figure 4: The SEMCAD X environment includes birdcages standardized for implant evaluation, import of the most advanced human models (e. g, Duke of the virtual family) for the manipulation of postural changes using SEMCAD Poser, and the introduction of imported CAD data of an implant into anatomically correct human models. Microwave Engineering ● 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.