7 .0 Guide Example - Altair University

1 ^ FEKOE xamples GuideSuite 2014 Copyright 1998 2014:EM Software & (Pty) Ltd32 Techno Avenue, Technopark, Stellenbosch, 7600, South AfricaTel:+27-21-831-1500, Fax:+27-21-880-1936E-Mail: ..1A Antenna synthesis+analysisA-1 Dipole Example ..A-1-1A-2 Dipole in front of a cube ..A-2-1A-3 Dipole in front of a plate ..A-3-1A-4 A monopole antenna on a finite ground plane ..A-4-1A-5 Yagi-Uda antenna above a real ground ..A-5-1A-6 Pattern optimisation of a Yagi-Uda antenna ..A-6-1A-7 Log periodic antenna ..A-7-1A-8 Microstrip patch antenna ..A-8-1A-9 Proximity coupled patch antenna with microstrip feed ..A-9-1A-10 Modelling an aperture coupled patch antenna .. A-10-1A-11 Different ways to feed a horn antenna .. A-11-1A-12 Dielectric resonator antenna on finite ground.

2 A-12-1A-13 A lens antenna with geometrical optics (GO) - ray launching .. A-13-1A-14 Windscreen antenna on an automobile .. A-14-1A-15 Design of a MIMO elliptical ring antenna (characteristic modes) .. A-15-1A-16 Periodic boundary conditions for array analysis .. A-16-1A-17 Finite array with non-linear element spacing .. A-17-1B Antenna placementB-1 Antenna coupling on an electrically large object ..B-1-1B-2 Antenna coupling using an ideal receiving antenna ..B-2-1B-3 Using a point source and ideal receiving antenna ..B-3-1C Radar cross section (RCS)C-1 RCS of a thin dielectric sheet ..C-1-1C-2 RCS and near field of a dielectric sphere ..C-2-1C-3 Scattering width of an infinite cylinder ..C-3-1C-4 Periodic boundary conditions for FSS characterisation ..C-4-1D EMC analysis+cable couplingD-1 Shielding factor of a sphere with finite conductivity.

3 D-1-1 May 2014 FEKO Examples GuideCONTENTSiiD-2 Calculating field coupling into a shielded cable ..D-2-1D-3 A magnetic-field probe ..D-3-1D-4 Antenna radiation hazard (RADHAZ) safety zones ..D-4-1E Waveguide+microwave circuitsE-1 A Microstrip filter ..E-1-1E-2 S-parameter coupling in a stepped waveguide section ..E-2-1E-3 Using a non-radiating network to match a dipole antenna ..E-3-1E-4 Subdividing a model using non-radiating networks ..E-4-1E-5 A Microstrip coupler ..E-5-1F Bio electromagneticsF-1 Exposure of muscle tissue using MoM/FEM hybrid ..F-1-1F-2 Magnetic Resonance Imaging (MRI) birdcage head coil Example ..F-2-1G Time domain examplesG-1 Time analysis of the effect of an incident plane wave on an obstacle ..G-1-1H Special solution methodsH-1 A Forked dipole antenna (continuous frequency range).

4 H-1-1H-2 Using the MLFMM for electrically large models ..H-2-1H-3 Horn feeding a large reflector ..H-3-1H-4 Optimise waveguide pin feed location ..H-4-1I User interface toolsI-1 POSTFEKO Application automation ..I-1-1J IndexIndex ..I-1 May 2014 FEKO Examples GuideINTRODUCTION1 IntroductionThisExamples guidepresents a set of simple examples which demonstrate a selection of thefeatures of the FEKO Suite. The examples have been selected to illustrate the features withoutbeing unnecessarily complex or requiring excessive run times. The input files for the examplescan be found in theexamples/ExampleGuide_modelsdirectory under the FEKO results are provided for these examples and in most cases, the*.pre,*.cfmand/or*.optfiles have to be generated by opening and re-saving the provided project files (*.)

5 Cfx) before thecomputation of the results can be initiated by running the FEKO preprocessor, solver or can be used in one of three ways. The first and recommended way is to construct the entiremodel in the CADFEKO user interface. The second way is to use CADFEKO for the model geome-try creation and the solution set up and to use scripting for advanced options and adjustment ofthe model (for Example the selection of advanced preconditioner options). The last way is to usethe scripting for the entire model geometry and solution set this document the focus is on the recommended approaches (primarily using the CADFEKO user interface with no scripting).Examples that employ only scripting are discussed in theScript Examplesguide. These exam-ples illustrate similar applications and methods to the examples in theExamples guideand it ishighly recommended that you only consider theScript Examplesif scripting-only examples arespecifically required.

6 It is advisable to work through theGetting started guideand familiariseyourself with theWorking with EDITFEKO section in theFEKO Users Manualbefore attemptingthe scripting only FEKO LITEFEKO LITE is a lite version of the FEKO Suite, which is limited with respect to problem size andtherefore cannot run all of the examples in this Guide . For more information on FEKO LITE,please see theGetting startedmanual and theInstallation to expectThe examples have been chosen to demonstrate how FEKO can be used in a selection of applica-tions with a selection of the available information regarding the creation and setup of the Example models for simulation isdiscussed, these Example descriptions are not intended to be complete step-by-step guides thatwill allow exact recreation of the models for simulation. This document rather presents a guidethat will help the user to discover and understand the concepts involved in various applicationsand methods that are available in FEKO, while working with the provided each Example , a short description of the problem is given, then the model creation is discussedafter which the relevant results are 2014 FEKO Examples GuideINTRODUCTION2 More examplesThis set of examples demonstrates the major features of FEKO.

7 For more step-by-step examples,please consult theGetting startedguide. Also consult the FEKO website1for more examples andmodels, specific documentation and other FEKO usage FAQ s and informationThe contact details for each FEKO distributor is available at Pleasecontact the distributor in your region about any FEKO queries or licences. For more technicalquestions, please contact the FEKO support team ( ). 2014 FEKO Examples GuideChapter AAntenna synthesis+analysisDIPOLE EXAMPLEA-1-1A-1 Dipole exampleKeywords:dipole, radiation pattern, far field, input impedanceThis Example demonstrates the calculation of the radiation pattern and input impedance for asimple half-wavelength dipole, shown in Figure A-1-1. The wavelength, , is 4 m ( 75 MHz),the length of the antenna is 2 m and the wire radius is 2 A-1-1: A 3D view of the dipole model with a voltage source excitation, symmetry and the far fieldpattern to be calculated in CADFEKO are DipoleCreating the modelThe steps for setting up the model are as follows: Define the following variables: lambda = 4(Free space wavelength.)

8 Freq = c0/lambda(Operating frequency.) h = lambda/2(Length of the dipole.) radius = 2E-3(Radius of the wire.) Create a line primitive with the start and end coordinates of (0,0,-h/2) and (0,0,h/2). Define a wire vertex port at the centre of the line. Add a voltage source to the wire port. Set the frequency to the defined 2014 FEKO Examples GuideDIPOLE EXAMPLEA-1-2 Requesting calculationsThis problem is symmetric around the z=0 plane. All electric fields will be normal to this plane,and therefore the symmetry is solution requests are: Create a vertical far field request. (-180 180 , with =0 where and denotes theangles theta and phi). Sample the far field at 2 informationUse thestandardauto-mesh setting with wire segment radius equal validateAfter the model has been meshed, runCEM validate. Take note of any warnings and any errors before running the FEKO solution ResultsA polar plot of the gain (in dB) of the requested far field pattern is shown in Figure the graph display settings, open the advanced dialog in the Axes group.

9 Set the maximumdynamic range of the radial axis to -10 A-1-2: A polar plot of the requested far field gain (dB) viewed in 2014 FEKO Examples GuideDIPOLE EXAMPLEA-1-3 Since the impedance is only calculated at a single frequency it can easily be read from the*.outfile. The OUT file can be viewed in the POSTFEKO*.outfile viewer, or in any other text fileviewer. An extract is shown OF THE VOLTAGE SOURCE NO. 1real part imag. part magnitude phaseCurrent in A in A/V in Ohm +01 +01 +01 in H , the impedance can be plotted as a function of frequency on a Cartesian graph orSmith chart in 2014 FEKO Examples GuideDIPOLE IN FRONT OF A CUBEA-2-1A-2 Dipole in front of a cubeKeywords:dipole, PEC, metal, lossy, dielectricA half wavelength dipole is placed three quarters of a wavelength away from a cube.

10 The radi-ation pattern is calculated and the effect of the nearby cube on the radiation pattern is demon-strated. Three different cubes are modelled in this Example . The first cube is PEC (perfectelectrically conducting), the second is a metal cube that has a finite conductivity and the thirdcube is made as a solid dielectric second and third models are an extension of the first model. The examples should be set A-2-1: A 3D view of the dipole with a metallic cube model (symmetry planes shown). Dipole and PEC cubeCreating the modelThe steps for setting up the model are as follows: Define the following variables: lambda = 4(Free space wavelength.) freq = c0/lambda(Operating frequency.) h = lambda/2(Length of the dipole.) radius = 2e-3(Wire radius of dipole.) Create a cube. The cuboid is created with theBase corner, width, depth, heightdefinitionmethod.