WIPL-D User's Manual

WIPL-D Software Electromagnetic Modeling of Composite Metallic and Dielectric Structures

WIPL-D team: Branko Kolundzija, Jovan Ognjanovic, Miodrag Tasic, Dragan Olcan, Drazen Sumic

Marija Bozic, Milan Kostic, Milos Pavlovic, Branko Mrdakovic

WIPL-D Pro v8.0 3D Electromagnetic Solver Professional Edition

Users Manual

WIPL-D Table of Contents I

Table of Contents

Table of Contents............................................................................................... I 1. Introduction (What Is WIPL-D?)..................................................... 1-1 1.1. Key Features.................................................................................... 1-1 1.2. List of Solvable Professional Problems........................................... 1-2 1.3. Intended Users ................................................................................. 1-3 1.4. Hardware and Software Requirements ............................................ 1-3 1.5. Questions or Comments .................................................................. 1-3 2. Getting Started................................................................................. 2-1 2.1. Installing WIPL-D ........................................................................... 2-1 2.2. Starting WIPL-D ............................................................................. 2-6 2.3. Navigation through WIPL-D ........................................................... 2-7 2.4. Exiting WIPL-D .............................................................................. 2-9 2.5. Getting Help .................................................................................... 2-9 3. Quick Tour ...................................................................................... 3-1 3.1. Define the Problem.......................................................................... 3-2 3.2. Edit the Input Data (Metallic Structure) .......................................... 3-4

3.2.1. Define the Operation Mode of the Structure............................... 3-5 3.2.2. Define the Frequency Range of the Analysis.............................. 3-5 3.2.3. Define the Structure Geometry ................................................... 3-7

3.2.3.1. Define Node Coordinates .................................................. 3-8 3.2.3.2. Define the Start and End Nodes and Radii for a Wire....... 3-8 3.2.3.3. Define the Corner Points of a Plate ................................... 3-9 3.2.3.4. Define the Wire-to-Plate Junction..................................... 3-9

3.2.4. Define the Excitation for the Structure ..................................... 3-10 3.2.5. Specify the Output Results ....................................................... 3-11

3.2.5.1. Specify the Directions for Radiation Calculations .......... 3-11 3.2.5.2. Calculate the Currents along Wires and Plates................ 3-12 3.2.5.3. Specify the Points for Near-Field Calculations ............... 3-12

3.3. Show 3-D Drawing of the Metallic Structure................................ 3-13 3.4. Save the Input Data ....................................................................... 3-14 3.5. Run the Analysis............................................................................ 3-15

II Table of Contents WIPL-D

3.6. List the Results ..............................................................................3-16 3.7. Print the Results .............................................................................3-16 3.8. Make 2-D and 3-D Graphs of the Results......................................3-17 3.9. Print and Export Graphs ................................................................3-18 3.10. Use Existing Data ..........................................................................3-18 3.11. Define the Problem (Composite Structure)....................................3-19 3.12. Edit the Input Data (Composite Structures) ...................................3-21

3.12.1. Define the Geometry of the Composite Structures...............3-21 3.12.1.1. Define Domains for the Composite Structures ................3-22 3.12.1.2. Define the Domain to Which the Wire Belongs ..............3-22 3.12.1.3. Define Domains of Metallic and Dielectric Plates ..........3-23

3.13. Show a 3-D Drawing of the Composite Structure .........................3-24 3.14. Compare Output Results for Different Projects .............................3-26 4. Basic Theory....................................................................................4-1 4.1. Electromagnetic modeling of metallic structures.............................4-1

4.1.1. Geometrical Modeling ................................................................4-2 4.1.1.1. Truncated Cones (Wires)...................................................4-4 4.1.1.2. Bilinear Surfaces (Plates) ..................................................4-6 4.1.1.3. Wire-to-Plate Junctions .....................................................4-7

4.1.2. Modeling of Currents ..................................................................4-9 4.1.2.1. Electric Field Integral Equation.........................................4-9 4.1.2.2. Approximation of Currents..............................................4-11 4.1.2.3. Treatment of Excitation...................................................4-16 4.1.2.4. The Galerkin Method ......................................................4-20

4.1.3. Evaluation of Antenna and Scatterer Characteristics ................4-21 4.1.3.1. Network Parameters ........................................................4-21 4.1.3.2. Current Distribution.........................................................4-23 4.1.3.3. Far-Field ..........................................................................4-23

4.2. Electromagnetic modeling of composite metallic and dielectric structures........................................................................................4-25

4.2.1. Geometrical Modeling ..............................................................4-26 4.2.2. Modeling of Currents ................................................................4-26 4.2.3. Evaluation of Antenna and Scatterer Characteristics ................4-28

5. Preview ............................................................................................5-1 5.1. Rotating, Moving and Scaling .........................................................5-2 5.2. Manipulating by the Mouse .............................................................5-3 5.3. Numerating the Entities ...................................................................5-4 5.4. Marking the Entities ........................................................................5-5 5.5. Marking the Entities from Tables and Editors .................................5-8 5.6. Marking the Entities by the Mouse..................................................5-9 5.7. Positioning to the Entities ..............................................................5-10 5.8. Selecting Visible Domains.............................................................5-11 5.9. Selecting the Plate Pattern .............................................................5-12

WIPL-D Table of Contents III

5.10. Configuring the Preview................................................................ 5-13 5.11. Create Menu .................................................................................. 5-17 5.12. Animation...................................................................................... 5-18 6. Plotting and Listing Results............................................................. 6-1 6.1. Plotting Results................................................................................ 6-1

6.1.1. Y, Z, S Parameters ...................................................................... 6-3 6.1.1.1. Port Impedances and Reference Planes............................. 6-4 6.1.1.2. Configuring the Smith Chart ............................................. 6-5 6.1.1.3. Fitting (Interpolation) ........................................................ 6-7

6.1.2. Far-Field ..................................................................................... 6-8 6.1.3. Current Distribution over Elements .......................................... 6-11 6.1.4. Near-field.................................................................................. 6-13 6.1.5. 3D Graph View (Rainbow Properties)...................................... 6-16 6.1.6. Animation ................................................................................. 6-17 6.1.7. Marker ...................................................................................... 6-17 6.1.8. Zoom Window.......................................................................... 6-20 6.1.9. Viewing Parametric Sweep Results .......................................... 6-20 6.1.10. Overlay................................................................................. 6-22

6.2. Listing Results ............................................................................... 6-23 6.2.1. Admittance, Impedance and S-parameters................................ 6-24 6.2.2. Far-Field ................................................................................... 6-25 6.2.3. Current Distribution over Elements .......................................... 6-26 6.2.4. Near-Field ................................................................................. 6-28 6.2.5. Input Data ................................................................................. 6-30

7. Basic Electromagnetic Modeling..................................................... 7-1 7.1. Metallic Structures........................................................................... 7-1

7.1.1. Wire Structures ........................................................................... 7-1 7.1.1.1. Linear Wire Scatterer (Project: Demo111)........................ 7-2 7.1.1.2. Linear Dipole Antenna (Project: Demo112) ..................... 7-3 7.1.1.3. Conical Dipole Antenna (Project: Demo113) ................... 7-4 7.1.1.4. Linear Array (Project: Demo114) ..................................... 7-5

7.1.2. Plate Structures ........................................................................... 7-6 7.1.2.1. Square Scatterer (Project: Demo121)................................ 7-7 7.1.2.2. Corner Reflector (Project: Demo122) ............................... 7-8 7.1.2.3. Cube Scatterer (Project: Demo123) .................................. 7-9 7.1.2.4. Quadrilateral Scatterer (Project: Demo124) .................... 7-10 7.1.2.5. Triangular Scatterer (Project: Demo125) ........................ 7-11 7.1.2.6. Polygonal (Wing) Scatterer (Project: Demo126) ............ 7-12 7.1.2.7. Large Plate Scatterer (Project: Demo127)....................... 7-13

7.1.3. Composite Wire and Plate Structures ....................................... 7-14 7.1.3.1. Dipole Antenna with Corner Reflector (Project: Demo131).. ......................................................................................... 7-14 7.1.3.2. Bowtie Antenna (Project: Demo132) .............................. 7-15

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7.1.3.3. Monopole Antenna Mounted on a Cube (Project: Demo133) .........................................................................................7-17 7.1.3.4. Missile (Project: Demo134).............................................7-18

7.2. Basic Electromagnetic Modeling of Composite Metallic and Dielectric Structures ......................................................................7-19

7.2.1. Pure Dielectric Structures .........................................................7-19 7.2.1.1. Dielectric Cube Scatterer (Project: Demo211) ................7-20 7.2.1.2. Inhomogeneous Dielectric Cube Scatterer (Project: Demo212)........................................................................7-21 7.2.1.3. Multilayered Dielectric Cube Scatterer (Project: Demo213).. .........................................................................................7-22

7.2.2. Composite Metallic and Dielectric Structures ..........................7-23 7.2.2.1. Coated Plate Scatterer (Project: Demo221) .....................7-24 7.2.2.2. Coated Plate Scatterer with Lossy Dielectric (Project: Demo222)........................................................................7-25 7.2.2.3. Coated Plate Scatterer with Multi-Layered Lossy Dielectric (Project: Demo222a) .......................................................7-25 7.2.2.4. Composite Prism Scatterer (Project: Demo223)..............7-28 7.2.2.5. Dipole Antenna Protruding From a Dielectric Cube (Project: Demo224)........................................................................7-28 7.2.2.6. Square Plate Scatterer Protruding From a Dielectric Box (Project: Demo225) .........................................................7-30

8. Loadings ..........................................................................................8-1 8.1. Distributed Loadings .......................................................................8-1

8.1.1. Electrically Short Dipole Antenna (Demo321) ...........................8-4 8.1.2. Dipole Antenna with Dielectric Radome (Demo322) .................8-5 8.1.3. Capacitively Loaded Dipole Antenna (Demo323)......................8-6

8.2. Concentrated Loadings ....................................................................8-7 8.2.1. Parallel Configuration of Two Impedances (Demo324) .............8-8 8.2.2. Monopole Antenna over a PEC Plane (Demo325) .....................8-8 8.2.3. Resistor (Demo326) ....................................................................8-9

9. Objects and Manipulations ..............................................................9-1 9.1. Objects .............................................................................................9-1

9.1.1. Sphere .........................................................................................9-2 9.1.2. Circle...........................................................................................9-4 9.1.3. Reflector......................................................................................9-6

9.1.3.1. Custom Shaped Reflector (user defined generatrix)..........9-7 9.1.3.2. Custom Shaped Reflector (user defined surface) ..............9-9

9.1.4. BoR (Body of Revolution) ........................................................9-12 9.1.5. BoT (Body of Translation)........................................................9-14 9.1.6. BoCC (Body of Constant Cut) ..................................................9-15 9.1.7. BoCG (Body of Connected Generatrices).................................9-17 9.1.8. Nodes and Circle Generatrix.....................................................9-18

WIPL-D Table of Contents V

9.1.9. Helix ......................................................................................... 9-18 9.2. Manipulations ................................................................................ 9-22

9.2.1. Group ........................................................................................ 9-23 9.2.2. Rotate........................................................................................ 9-24 9.2.3. Move......................................................................................... 9-25 9.2.4. Copy ......................................................................................... 9-25 9.2.5. Generators (Gen.) ..................................................................... 9-26 9.2.6. Junction (Jun.)........................................................................... 9-27 9.2.7. Edge.......................................................................................... 9-28 9.2.8. RV-plates .................................................................................. 9-32

9.3. Structure Tree ................................................................................ 9-32 9.3.1. Overview of Model Structure and History................................ 9-33 9.3.2. Selecting Entities ...................................................................... 9-35 9.3.3. Operations on Entities............................................................... 9-35

10. Symbolic Dimensioning ................................................................ 10-1 11. Import ............................................................................................ 11-1 12. Creating Structures by the Mouse.................................................. 12-1 12.1. New Nodes .................................................................................... 12-2 12.2. New Wires ..................................................................................... 12-2 12.3. New Plates ..................................................................................... 12-4 12.4. New Generator............................................................................... 12-5 12.5. New Generatrix ............................................................................. 12-6 12.6. Edge............................................................................................... 12-7 12.7. Grids .............................................................................................. 12-8 12.8. Intersection .................................................................................. 12-11 12.9. Pattern.......................................................................................... 12-12 12.10. Dimensioning .............................................................................. 12-16 12.11. Group........................................................................................... 12-18 13. Using Symmetry in the Analysis of a Problem.............................. 13-1 13.1. Dipole Antenna (xOy Antisymmetry) (Project: Demo331)........... 13-3 13.2. Dipole Antenna (xOy Symmetry) (Project: Demo332) ................. 13-4 13.3. Dipole Antenna with a Corner Reflector (yOz Antisymmetry, xOz Symmetry) (Project: Demo333) .................................................... 13-5 13.4. Linear Array Antenna (xOz Symmetry) (Project: Demo334) ....... 13-6 13.5. Linear Array (xOy Antisymmetry) (Project: Demo335) ............... 13-7 13.6. Corner Reflector (xOz Symmetry) (Project: Demo336)................ 13-8 13.7. Corner Reflector (xOz Antisymmetry) (Project: Demo337) ......... 13-9 13.8. Monopole Antenna in the Middle of a Circular Disk (xOz Rotation) (Project: Demo338) ..................................................................... 13-10 14. Apertures in PEC and PMC Planes ............................................... 14-1 14.1. Slot Between Two Half Spaces ..................................................... 14-1 14.2. Cavity Backed Slot ........................................................................ 14-2 14.3. Hemispherical Dielectric Resonator above Cavity Backed Slot.... 14-3

VI Table of Contents WIPL-D

14.4. Horn Aperture in PEC Plane..........................................................14-3 14.5. Horn Aperture in PEC Plane with Two Symmetry Planes.............14-4 14.6. Monopole Antenna above PEC Plane Fed by a Coaxial Line.....14-5 14.7. Monopole Antenna above PEC Plane Fed by a Delta Generator...... .......................................................................................................14-6 14.8. RCS from a Slot in an Infinite PEC Plane .....................................14-7 15. Improving, Accelerating and Checking Solutions .........................15-1 15.1. Topological Checker......................................................................15-1 15.2. Choosing the Accuracy of Integrals Used in the Analysis.............15-3 15.3. Choosing the Order for the Current Approximation ......................15-4 15.4. Increasing Reference Frequency and Limiting Maximum Patch Size .. .......................................................................................................15-6 15.5. Simulation of Antenna Placement .................................................15-6 15.6. Choosing the Type of Matrix Inversion.......................................15-10 15.7. Outcore Solver .............................................................................15-11 15.8. Iterative and MLFMM solver ......................................................15-12 15.9. Choosing the Number of Decimal Digits for Matrix Inversion ...15-15 15.10. Selecting the Basis Functions ......................................................15-16 15.11. Running Multiple simulations by Using Batch............................15-17 15.12. Checking the Quality of Solution by Power Balance...................15-19 15.13. Checking the Quality of Solution from the Near Field ................15-22 16. Advanced Wire Modeling..............................................................16-1 16.1. Antennas above a Ground Plane ....................................................16-1 16.2. Modeling of the Wire End Effects and the Wire Feed Area ..........16-2 16.3. Coaxial Line Excitation (Infinite Ground Plane) ...........................16-5 16.4. Coaxial Line Excitation (Finite Ground Plane) .............................16-7 16.5. Plate Modeling of Wire Structures ................................................16-8 17. Modeling of Microstrip Structures.................................................17-1 17.1. Basic Modeling (Infinite Ground Plane)........................................17-1 17.2. Single Edging ................................................................................17-3 17.3. Double Edging ...............................................................................17-4 17.4. Finite Thickness Metallization.......................................................17-5 17.5. Finite Ground Plane (Basic Model) ...............................................17-6 17.6. Imaging in Finite Ground Plane.....................................................17-6 18. Complex Examples ........................................................................18-1 18.1. Electrically Long Monopole Antenna above a Ground Plane........18-1 18.2. Spherical Scatterer .........................................................................18-2 18.3. Log-Periodic Antennas ..................................................................18-3 18.4. Monopole Antenna on the Roof of a Vehicle ................................18-4 18.5. Open-Ended Waveguide Antenna..................................................18-4 18.6. Horn Antenna.................................................................................18-6 18.7. Paraboloidal Reflector Antenna with a Feeding Structure.............18-7

WIPL-D Table of Contents VII

18.8. Hemispherical Dielectric Resonator Antenna above a Finite Ground Plane .............................................................................................. 18-8 18.9. Dielectric Rod Antenna ................................................................. 18-9 18.10. Handheld Set in the Vicinity of a Human Head .......................... 18-10 18.11. Microstrip Patch Antenna Fed by a Microstrip Line ................... 18-11 18.12. TV-UHF Panel Antenna with a Radome ..................................... 18-12 19. Antenna above the Real Ground.................................................... 19-1 19.1. Introduction ................................................................................... 19-1 19.2. Influence of the Ground on the Radiation Pattern ......................... 19-2 19.3. Influence of the Ground on the Current Distribution..................... 19-3 20. Making the Documentation ........................................................... 20-1 21. De-embedding Technique.............................................................. 21-1 21.1. Introduction ................................................................................... 21-1 21.2. Theoretical Basis: S-parameters of the 2-port Feeding Network... 21-2 21.3. S-parameters of a Basic n-port Circuit .......................................... 21-3 21.4. S-parameters of a Full Network..................................................... 21-6 21.5. S-parameters of the 2-port Feeding Networks ............................... 21-7 21.6. Input Data for an Analysis of Feeding Networks .......................... 21-7 21.7. Option Feed ................................................................................. 21-10 21.8. S-parameters of the Basic Network ............................................. 21-12 22. Parametric Sweep .......................................................................... 22-1 22.1. Introduction ................................................................................... 22-1 22.2. Starting WIPL-D Parametric Sweeper........................................... 22-1 22.3. Specifying Sweep Parameters and Their Ranges .......................... 22-2 22.4. Running the Parametric Sweeper................................................... 22-3 22.5. Parametric Sweep Tips .................................................................. 22-3 22.6. Parametric Sweep Example ........................................................... 22-3 23. Show.............................................................................................. 23-1 23.1. Rotating, Moving and Scaling ....................................................... 23-2 23.2. Manipulating by the Mouse........................................................... 23-2 23.3. Numerating the Entities ................................................................. 23-4 23.4. Marking the Entities ...................................................................... 23-4 23.5. Marking the Entities by the Mouse................................................ 23-7 23.6. Positioning to the Entities.............................................................. 23-8 23.7. Selecting Visible Domains ............................................................ 23-9 23.8. Selecting the Plate Pattern ........................................................... 23-10 23.9. Configuring the Show.................................................................. 23-11 23.10. Final Meshing of 3D Structure .................................................... 23-14

23.10.1. Additional Meshing due to Junctions................................. 23-14 23.10.2. Additional Meshing due to Edging .................................... 23-17 23.10.3. Partition of Large Plates and Long Wires .......................... 23-18 23.10.4. Partition of Non-Convex Plates ......................................... 23-18

24. WIPL-D Optimizer ........................................................................ 24-1

VIII Table of Contents WIPL-D

24.1. Introduction ...................................................................................24-1 24.2. Starting the WIPL-D Optimizer.....................................................24-2 24.3. Specifying Optimization Method(s), Number of Iterations (Solver Calls), and Optimizer Options .......................................................24-3 24.4. Specifying Optimization Variables and Their Ranges...................24-6 24.5. Specifying the Criterion (or Criteria) For Optimization ................24-6 24.6. Running the Optimization..............................................................24-9 24.7. Optimization Tips ..........................................................................24-9 24.8. Optimization Examples................................................................24-10 24.9. Available Optimization Methods and Their Specific Parameters 24-12

24.9.1. Simplex ..............................................................................24-13 24.9.2. Gradient..............................................................................24-13 24.9.3. Random ..............................................................................24-14 24.9.4. Systematic Search ..............................................................24-15 24.9.5. Genetic Algorithm..............................................................24-16 24.9.6. Simulated Annealing (SA) .................................................24-18 24.9.7. Particle Swarm Optimization (PSO) ..................................24-19

25. AW Modeler ..................................................................................25-1 25.1. Basic Operations And Concepts ....................................................25-1

25.1.1. Starting AW Modeler ...........................................................25-1 25.1.2. Operation Modes and Corresponding Cursors .....................25-2 25.1.3. Menus...................................................................................25-3 25.1.4. Opening Project....................................................................25-3

25.1.4.1. Supported File Formats ...................................................25-4 25.1.5. Saving Project ......................................................................25-4 25.1.6. Viewing Structure ................................................................25-4

25.1.6.1. Spin..................................................................................25-4 25.1.6.2. Pan...................................................................................25-5 25.1.6.3. Zoom ...............................................................................25-5 25.1.6.4. Projections .......................................................................25-6

25.2. Symbols .........................................................................................25-7 25.2.1. Symbols Parameters .............................................................25-7

25.2.1.1. Symbol Name ..................................................................25-7 25.2.1.2. Symbol Expression..........................................................25-7 25.2.1.3. Symbol value...................................................................25-8

25.2.2. Symbols Window.................................................................25-8 25.2.2.1. Activation ........................................................................25-8 25.2.2.2. Functional Parts ...............................................................25-9 25.2.2.3. Managing Symbols..........................................................25-9

25.2.3. Using Symbols ...................................................................25-10 25.2.4. Symbols Generated by AW Modeler .................................25-10 25.2.5. Closing Symbols Window..................................................25-11

25.3. Grids ............................................................................................25-11

WIPL-D Table of Contents IX

25.3.1. Grid Types ......................................................................... 25-11 25.3.2. Grid Parameters Common to Uniform and Non-uniform Grids . ........................................................................................... 25-12

25.3.2.1. Perpendicular Axis ........................................................ 25-12 25.3.2.2. Coordinate along Perpendicular Axis............................ 25-12 25.3.2.3. Angle of Rotation.......................................................... 25-12 25.3.2.4. Shift in Grids Plane ....................................................... 25-12

25.3.3. Grid Parameters Unique to Uniform Grids ........................ 25-12 25.3.3.1. Edging Lines ................................................................. 25-12 25.3.3.2. Number of Steps............................................................ 25-12

25.3.4. Grid Parameters Unique to Non-uniform Grids ................. 25-12 25.3.4.1. Coordinates of Lines ..................................................... 25-12

25.3.5. Grids Window.................................................................... 25-13 25.3.5.1. Activation...................................................................... 25-13 25.3.5.2. Functional Parts............................................................. 25-13 25.3.5.3. Managing Grids............................................................. 25-14

25.3.6. Using Grids ........................................................................ 25-14 25.3.7. Closing Grids Window....................................................... 25-15

25.4. Creating Structure........................................................................ 25-15 25.4.1. Entities ............................................................................... 25-15

25.4.1.1. Polygons........................................................................ 25-15 25.4.1.2. Wires ............................................................................. 25-15

25.4.2. Overlapping of Polygons ................................................... 25-15 25.4.3. Hole Polygons.................................................................... 25-16 25.4.4. Circle Polygons.................................................................. 25-16 25.4.5. Combination of Entities ..................................................... 25-16

25.4.5.1. Substrate........................................................................ 25-16 25.4.5.2. Via................................................................................. 25-16 25.4.5.3. Feeder............................................................................ 25-16

25.4.6. Creation Modes.................................................................. 25-17 25.4.6.1. Create Polygon Mode.................................................... 25-17 25.4.6.2. Create Wire Mode ......................................................... 25-18 25.4.6.3. Create Feeder Mode ...................................................... 25-18 25.4.6.4. Create Grid Line Mode ................................................. 25-18

25.4.7. Procedures for Creating Nodes .......................................... 25-19 25.4.8. Creating Entities and Combination of Entities................... 25-19

25.4.8.1. Creating Polygon........................................................... 25-19 25.4.8.2. Creating Wire ................................................................ 25-20 25.4.8.3. Creating Circle .............................................................. 25-20 25.4.8.4. Creating Substrate ......................................................... 25-20 25.4.8.5. Creating Via .................................................................. 25-21 25.4.8.6. Creating Feeder ............................................................. 25-21 25.4.8.7. Creating Grid Line ........................................................ 25-21

X Table of Contents WIPL-D

25.5. Modifying Structure.....................................................................25-21 25.5.1. Modify Polygons Mode......................................................25-22

25.5.1.1. Activating Modify Polygons Mode ...............................25-22 25.5.1.2. Active Polygon and Active Node ..................................25-22 25.5.1.3. Popup Menu ..................................................................25-22 25.5.1.4. Edit Panel ......................................................................25-23 25.5.1.5. Changing Active Polygon..............................................25-23 25.5.1.6. Changing Active Node ..................................................25-23 25.5.1.7. Direct Switch to Modify Wires Mode ...........................25-23 25.5.1.8. Change of View.............................................................25-23 25.5.1.9. Moving Active Node .....................................................25-23 25.5.1.10. Adding Node to Active Polygon...............................25-24 25.5.1.11. Deleting Active Polygons Node ...............................25-24 25.5.1.12. Modifying Active Polygons Properties.....................25-24 25.5.1.13. Checking Polygons Status ........................................25-25 25.5.1.14. Changing Drawing Order of Active Polygon ...........25-25 25.5.1.15. Exiting Modify Polygons Mode ...............................25-25

25.5.2. Modify Wires Mode...........................................................25-25 25.5.2.1. Activating Modify Wires Mode ....................................25-25 25.5.2.2. Active Wire and Active Node .......................................25-25 25.5.2.3. Popup menu...................................................................25-26 25.5.2.4. Edit Panel ......................................................................25-26 25.5.2.5. Changing Active Wire...................................................25-26 25.5.2.6. Direct Switch to Modify Polygons Mode......................25-26 25.5.2.7. Change of View.............................................................25-27 25.5.2.8. Moving Active Node .....................................................25-27 25.5.2.9. Modifying Active Wire Properties ................................25-27 25.5.2.10. Exiting Modify Wires Mode.....................................25-27

25.6. Manipulations ..............................................................................25-28 25.6.1. Selecting Entities................................................................25-28 25.6.2. Change of View..................................................................25-29 25.6.3. Entities Colors....................................................................25-29 25.6.4. Changing Polygon or Wire Properties................................25-29 25.6.5. Displacing Selected Entities...............................................25-30 25.6.6. Copying Selected Entities ..................................................25-30 25.6.7. Enclosing Selected Entities ................................................25-31 25.6.8. Metallization ......................................................................25-31 25.6.9. Deleting Selected Entities ..................................................25-33

25.7. Exporting Model to WIPL-D.......................................................25-33 25.7.1. Units ...................................................................................25-33 25.7.2. Analysis Settings ................................................................25-33 25.7.3. Meshing of Polygons..........................................................25-34 25.7.4. Creating WIPL-D File ........................................................25-36

WIPL-D Table of Contents XI

25.7.5. Opening and Optimizing in WIPL-D................................. 25-37 25.8. Modeling Example ...................................................................... 25-37 25.9. Creating Model in AutoCAD ...................................................... 25-41 25.10. Reference..................................................................................... 25-45

25.10.1.1. How to Open Project ................................................ 25-45 25.10.1.2. How to Save New Project......................................... 25-46 25.10.1.3. How to Save Existing Project................................... 25-46 25.10.1.4. How to Save Existing Project under Different Name25-46 25.10.1.5. How to Spin Downward ........................................... 25-46 25.10.1.6. How to Spin Clockwise ............................................ 25-46 25.10.1.7. How to Pan ............................................................... 25-46 25.10.1.8. How to Zoom Interactive.......................................... 25-46 25.10.1.9. How to Zoom Window............................................. 25-47 25.10.1.10. How to Zoom All ..................................................... 25-47 25.10.1.11. How to View Projections.......................................... 25-47 25.10.1.12. How to Activate Symbols Window.......................... 25-47 25.10.1.13. How to Create New Symbol at End of Symbols List25-47 25.10.1.14. How to Create New Symbol at Arbitrary Position of Symbols List............................................................. 25-47 25.10.1.15. How to Find Symbol in Symbols List ...................... 25-48 25.10.1.16. How to Delete Symbol ............................................. 25-48 25.10.1.17. How to Delete All Unused Symbols......................... 25-48 25.10.1.18. How to Activate Grids Window ............................... 25-48 25.10.1.19. How to Create Grid .................................................. 25-48 25.10.1.20. How to Modify Grid................................................. 25-48 25.10.1.21. How to Copy Grid .................................................... 25-48 25.10.1.22. How to Delete Grid .................................................. 25-49 25.10.1.23. How to Create Polygon ............................................ 25-49 25.10.1.24. How to Create Wire.................................................. 25-49 25.10.1.25. How to Create Circle ................................................ 25-49 25.10.1.26. How to Create Substrate ........................................... 25-49 25.10.1.27. How to Create Via .................................................... 25-49 25.10.1.28. How to Create Feeder ............................................... 25-49 25.10.1.29. How to Create Grid Line .......................................... 25-50 25.10.1.30. How to Move Polygon Node .................................... 25-50 25.10.1.31. How to Add Node to Polygon .................................. 25-50 25.10.1.32. How To Delete Polygon Node.................................. 25-50 25.10.1.33. How to Check Polygon Status .................................. 25-50 25.10.1.34. How to Change Drawing Order of Polygon ............. 25-51 25.10.1.35. How to Change Polygon Properties.......................... 25-51 25.10.1.36. How to Move Wire Node ......................................... 25-51 25.10.1.37. How to Change Wire Properties............................... 25-51 25.10.1.38. How to Change Entities Color Mode........................ 25-51

XII Table of Contents WIPL-D

25.10.1.39. How to Change Properties of Group of Polygons.....25-52 25.10.1.40. How to Change Properties of Group of Wires..........25-52 25.10.1.41. How to Move Entities ...............................................25-52 25.10.1.42. How to Rotate Entities..............................................25-52 25.10.1.43. How to Copy and Move Entities...............................25-53 25.10.1.44. How to Copy and Rotate Entities .............................25-53 25.10.1.45. How to Enclose Polygons .........................................25-53 25.10.1.46. How to Add Metallization to Metalic Polygons .......25-53 25.10.1.47. How to Remove Metallization from Polygons .........25-54 25.10.1.48. How to Remove Metallization from All Polygons ...25-54 25.10.1.49. How to View Metallization.......................................25-54 25.10.1.50. How to Delete Entities..............................................25-54 25.10.1.51. How to Create WIPL-D File .....................................25-54

25.11. Literature .....................................................................................25-55 26. WIPL-D Time Domain Solver.......................................................26-1 26.1. Introduction ...................................................................................26-1 26.2. Starting WIPL-D Time Domain Solver .........................................26-2 26.3. Specifying Waveforms of the Time-Domain Excitations ..............26-3 26.4. Specifying Time Interval and Number of Time Samples at Which Time-Domain Response is Calculated...........................................26-6 26.5. Specifying Time-Domain Outputs.................................................26-8 26.6. Running Time Domain Simulation..............................................26-10 26.7. Examining Output Results ...........................................................26-11 26.8. Time Domain Simulation Tips ....................................................26-11 26.9. Time Domain Analysis Examples ...............................................26-12

26.9.1. Resistive Loop Excited by Gaussian Monocycle ...............26-12 26.9.2. Dipole Antenna Excited with Gaussian Pulse ....................26-18 26.9.3. Plate Scatterer.....................................................................26-24

26.10. Time Domain Analysis Theory....................................................26-28 27. Frequently Used Shortcuts.............................................................27-1 Index 27-I

WIPL-D Introduction (What Is WIPL-D?) 1-1

1. Introduction (What Is WIPL-D?)

WIPL-D is an extremely powerful program that allows fast and accurate analysis of metallic and/or dielectric/magnetic structures (antennas, scatterers, passive microwave circuits, etc.). The calculations are done in the frequency domain.

This user-friendly program enables you to define the geometry of any structure in an interactive way as combination of wires, plates and material objects. It continuously displays the 3-D structure as it evolves through its definition.

As an output, WIPL-D provides the current distribution on the structure, radiation pattern, near-field distribution, admittance, impedance, and s-parameters at the predefined feed points. WIPL-D also provides you with a variety of printer-based and/or graphic output capabilities, including 2-D and 3-D graphs of the parameters of interest.

A user does not need not to know the analysis method to use the program. WIPL-D efficiently executes most of the desired computations in reasonable time on any Windows based PC system, thereby making the software ideal for computer-aided design.

1.1. Key Features

The composite structure is characterized by equivalent surface electric currents over metallic portions and equivalent surface electric and magnetic currents over dielectric material surfaces. In this code it is possible to include lossy materials with high complex permeability and permittivity.

Concentrated and distributed loadings can be applied to the metallic structure, thus simulating lumped elements, losses due to the skin effect, surface roughness, etc.

1-2 Introduction (What Is WIPL-D?) WIPL-D

Flexible geometrical modeling includes cylindrical and conical wires, quadrilateral plates which may characterize metallic or lossy/lossless dielectric/magnetic surfaces, wire-to-plate junctions, and protrusions, so that almost any finite composite structure can be precisely modeled.

Accurate current modeling is based on polynomial approximation in conjunction with the Galerkin method applied to surface integral equations, resulting in an accurate and efficient method.

Custom codes include generation of complex objects (like BOR, BOT, etc.), manipulations with WIPL-D entities (rotation, scaling, multiplication, etc.), importing of already defined structures, and symbolic dimensioning of the structures, providing an environment for fast creation of new and easy modification of old structures,

A variety of graphic plotting options are available, like overlaying 2-D graphs from different projects, or coloring and shading 3-D drawings of edited structure, enabling you to make attractive reports with ease.

1.2. List of Solvable Professional Problems

We list here some of the problems that can be treated with ease using this software. However, the list is not exhaustive:

Input impedance and radiation pattern of different types of antennas, both planar and conformal: Yagi-Uda arrays, log-periodic antennas, wire and strip helical antennas, horn antennas excited by probe fed wave guides, reflector antennas with feed structures, slotted wave guide planar array, micro strip patch antennas over finite substrate, dielectric rod antennas, dielectric resonator antennas, dielectric horn antennas, etc.

Impedance, admittance, and s-parameters of the multiport devices (e.g., microwave circuits and antenna arrays).

Antenna characteristics when they are mounted on vehicles (e.g., monopole antenna mounted on a car, airplane, or boat).

Characterization of near fields in a human head near a telephone handset. This allows for prediction of radiation hazards.

Influence of radome on the antenna characteristics. Scattering from vehicles coated by layered lossy dielectric/magnetic

materials.

WIPL-D Introduction (What Is WIPL-D?) 1-3

1.3. Intended Users

This versatile computer program is intended to be used by engineers, graduate students, and scientists involved in the analysis and design of various types of antennas, scatterers, and passive microwave circuit components.

The program is useful for radio engineering, microwaves, radar applications, electromagnetic compatibility, and communications. It can also be used for predicting electromagnetic fields inside biological bodies, making it a good tool for defining the parameters of radiation hazards or in medical applications.

1.4. Hardware and Software Requirements

The program runs on a minimal configuration consisting of a Pentium processor and other related 100% compatible computers, running Win 98, Win NT, Win ME, Win 2000, Win XP or Win Vista. A minimum of 256 MB RAM and 256 MB hard disk space is required. Support for graphics, printers, and mouse is provided by Windows.

1.5. Questions or Comments

If you have any questions or comments, please contact: [email protected]

WIPL-D Getting Started 2-1

2. Getting Started

Before getting started, check the hardware and software requirements for your PC outlined in the previous chapter. Start-up for WIPL-D includes the following steps: installing the program, running the program, getting help in the program, and exiting the program.

2.1. Installing WIPL-D

Start Windows. Insert distribution CD-ROM into the disc drive.

Autorun.exe starts and the WIPL-D 3D EM Solver Launcher appears, as shown to the right.

If autorun.exe doesnt start for some reason, explore distribution CD-ROM and start setup.exe.

Clock Next to start the installation.

2-2 Getting Started WIPL-D

Destination Location dialog box opens, as shown to the right.

Select destination folder where WPL-D will be installed by clicking Browse button. By default, it is C:\Program Files\ WIPL-D.

Click Next to continue.

Select Start Menu Programs Group dialog box opens, as shown to the right. Select the name of the Programs group in Start menu where shortcut to WIPL-D will be put. If you wish to create the shortcut on the desktop, tick Create Desktop Shortcut(s).


Start Installation dialog box appears, as shown to the right.



Installation progress dialog box appears, as shown to the right.

After the installation, Install Drivers dialog box opens, as shown to the right.

This starts the installation of drivers for hard key.


The License Agreement dialog box appears, as shown to the right.

Click I accept the terms in the license agreement.

Print the agreement by clicking Print.



Driver Setup Type dialog box appears, as shown to the right.

Select type Complete to install all features of the driver.


Ready to install the Program dialog box appears, as shown to the right.

Click Install to start driver installation.

After the installation, the Installation Complete dialog box opens as shown to the right.

Click Finish to finish the installation.


The message WIPL-D 3D EM Solver has been successfully installed appears.

Click Finish to finish the installation.

Before changes take effect the system must be restarted.

Click OK to restart the system, or Cancel to restart it later

After restart WIPL-D is ready to run in the Windows environment.


2.2. Starting WIPL-D

To start WIPL-D, double-click the WIPL-D icon . This command invokes the shell program (WIPL.exe). The starting screen as shown below appears. The initial password is WIPL and it can be changed in Configure > Password.

To obtain the Main screen, click OK. The Main screen appears, as shown below.


2.3. Navigation through WIPL-D

All problems to be analyzed by WIPL-D are organized in projects. A project consists of input data defining the problem and the output data representing the analysis results. So, the basic seven functions of WIPL-D involve managing the projects, allow interactive data entry, running the analysis, inspecting the output results, managing the layout windows, configuring the project, and using help. These functions are carried out by using more than 100 different commands.

All commands can be accessed starting from the Main menu bar. WIPL-D has the structure of a screen/menu/window hierarchy tree. Select options in the Main menu bar to open the menus corresponding to basic WIPL-D functions. Select options in these menus to open submenus, dialog boxes, tables, editors and screens. Locate the Main menu bar at the top of the Main Screen:


The basic way of selecting an option is by clicking (using a mouse). Once a dialog box is opened, it must be closed before selecting a new command. Tables, editors, and screens can be simultaneously displayed, but only one can be active at a time. Click the desired table, editor or screen to activate it.

Dialog boxes, tables, and editors contain pages, edit fields, combo boxes, radio buttons, and sliders. Click the desired page to activate it, the desired radio button to activate the attached option, and/or the desired edit field to activate it. Click the desired combo box to open the combo list and click the desired option in the list to select it. Drag the desired slider, pull, and drop at the desired position.

Alternatively, the most important commands can be directly accessed by clicking the tools in the Main toolbar. Locate the Main toolbar at the top of the Main Screen, just beneath the Main menu bar, which looks like:

After pressing Alt-F, two light bars appear in the Main screen. The first light bar points to the File option in the Menu bar, and the File menu opens. The second light bar points to the New option in the File menu. Press the Left and Right Arrow keys to move the first light bar through the Menu bar, which automatically opens the menus File, Edit, Run, Output, Configure, Window and Help. Press the Up and Down arrow keys to move the second light bar through the menu selected by the first light bar. Press Enter to choose a selected option.

To navigate through various dialog boxes, tables, and editors use arrow keys and the Tab key, which is often more comfortable than using the mouse.


2.4. Exiting WIPL-D

To exit WIPL-D, use the following procedure:

Click File in the Main menu bar. The File menu opens, as shown to the right.

Click Exit in the File menu. Alternatively, exit WIPL-D in

the same way as youd close any window:

Press Alt-F4, or Click (border icon).

2.5. Getting Help

WIPL-D has a context-sensitive, on-line system of Help windows, which can be used following any standard Windows procedure. Electronic version of WIPL-D manual is also available. PDF file is located in the folder Documentation in your respective WIPL-D installation folder.

Select the Help option in the Main menu bar. The Help menu opens. It contains three entries: Contents and Index , Quick Tour and About.

Click the Contents and Index option. The Help Topics dialog box opens. It contains pages: Contents, Index, and Find. By default, the Contents page opens. The WIPL-D Contents page consists of the Reference book only.

Click the Reference book twice. Four sections are displayed: Commands, Entities, Menus, and Toolbars, as shown below.


By clicking a chapter twice, the corresponding Help window opens, containing the list of entries (hotspots). For example, click the Command chapter. The Command Help window opens.


Clicking a hotspot opens the Help window that corresponds to the selected entry. For example, click About. The About Help window opens.

Alternatively, the Help windows can be accessed from the Index page of the Help Topics dialog box, where they are arranged in alphabetical order.

The Help windows can be accessed directly from menus, submenus, dialog boxes, tables, editors, and screens. If a dialog box is opened, or a table, editor, or screen is active, press F1 to open the corresponding Help window. If an option is selected in a menu bar, menus, or submenu, press F1 to open the corresponding Help window.

WIPL-D Quick Tour 3-1

3. Quick Tour

Electromagnetic modeling by WIPL-D usually includes the following steps: Defining the problem Editing the input data Checking the data provided by using the Preview of the structure and the

topological Checker Running the analysis Listing results Plotting 2D and 3D graphs of the computed results Saving the input data for the next analysis

The first three steps are simpler for pure metallic structures than for composite metallic and dielectric structures. Hence, we start this quick tour with modeling of metallic structures. Let us configure WIPL-D for modeling of metallic structures only.

3-2 Quick Tour WIPL-D

Select the Structure option in the Configure menu (Main menu bar). The Structure dialog box opens.

Select the Metallic option and press OK. The Structure dialog box closes and WIPL-D is now configured for analyzing metallic structures only.

3.1. Define the Problem

Any metallic antenna, scatterer, microwave device or an EMC facility can be considered to be composed of wires and plates situated in vacuum. Electromagnetic modeling of such structures consists of three parts:

Geometrical modeling of a real structure Determination of the currents distributed over the geometrical model Calculation of the quantities of interest by post processing the computed

currents The main task of the user in an electromagnetic modeling is to create an

appropriate geometrical model of the structure to be analyzed and to define the excitation for that model. The rest of the analysis is carried out by WIPL-D.

To make an adequate geometrical model of the structure of interest, you should follow some basic rules. Basically, the following points should be remembered:

Geometry of wires is approximated by right truncated cones. Geometry of plates is approximated by quadrilaterals (bilinear surfaces).

In a real situation, any geometry can be approximately modeled (e.g., in the case of metallic sphere). Models that are more precise usually require more approximating elements, resulting in longer analysis time. Hence, an effort should be made to create as simple geometrical model as possible, which will still provide acceptable results.


For example, let us consider an FM monopole antenna mounted on a roof of a vehicle. A possible, relatively precise geometrical model of this structure is shown above. However, in many situations it is not necessary to model the complete structure. For example, in the case of admittance calculations, it is enough to take into account only the interactions between monopole antenna and the roof of the vehicle. As an example in this chapter, we show how this simple structure is analyzed by WIPL-D.

Example:

The given structure operates as an antenna in the frequency range of 88 to 112 MHz.

The monopole antenna is a simple wire completely determined by its starting and ending radii and starting and ending nodes:

r1 = 15 mm

r2 = 3 mm

n1 (0 m, 0.3 m, 0 m) n2 (0 m, - 0.3 m, 0.6 m)

The plate is completely determined by its four corner points (nodes):


n3 ( 0.5 m, - 0.8 m, 0 m) n4 (- 0.5 m, - 0.8 m, 0 m)

n5 ( 0.55 m, 0.8 m, 0 m) n6 (- 0.55 m, 0.8 m, 0 m)

Wire is connected to the plate at node n1. The antenna is driven by a generator placed at node n1, with reference

direction to node n2. The results of interest are the antenna admittance computed at seven

equispaced frequencies, and the corresponding antenna directive gain for a space between planes = 90 and = 360, with 28 directions along angle and 19 directions along angle from = - 90 to = 90.

3.2. Edit the Input Data (Metallic Structure)

All input data is divided into nine groups:

Operation mode Frequency range Structure geometry Loadings Excitation

Symmetry planes Output Results calculations Options Symbols

The groups Symmetry planes, Options, and Symbols should only be used by advanced users, and so they will not be discussed in this tour.

Click Edit in the Main menu bar. The Edit menu is displayed above.


3.2.1. Define the Operation Mode of the Structure

A combined wire and plate structure can be an antenna (microwave device, EMC facility) or a scatterer. In general, an antenna has more than one port. The program offers two modes of operation for antennas: ANTENNA (all generators) and ANTENNA (one generator at time). In the first option, all ports are simultaneously excited, while in the second option, the antenna is assumed to be driven one port at a time (while all the other ports are short-circuited). If an antenna has only one port, both options give the same results.

Select Operation in the Edit menu. The Operation dialog box opens.

The activated radio button denotes the currently selected mode of operation. Initially, the default mode is ANTENNA (one generator at time).

Click ANTENNA (all generators). The dialog box looks as shown to the right.

Press OK. The dialog box closes.

3.2.2. Define the Frequency Range of the Analysis

The analysis of the structure of interest is performed at one or more frequencies. The frequency range is defined by the start and stop frequencies and the number of frequencies. The computation is performed at a number of equally spaced frequencies. If the number of frequencies is one, the analysis is performed only at the start frequency.


Select Frequency in the Edit menu. The Frequency dialog box opens.

Type the number 88 in the Start Frequency edit field. Type the number 112 in the Stop Frequency edit field. Type the number 7 in the Number of Frequencies edit field.

Click OK. The dialog box closes.

To specify multiple frequency ranges click More. Frequency dialog box opens.

To define 2 frequency ranges, type 2 in Number of frequency ranges. Type 88 in the Start, 112 in Stop edit field and 7 in the Number edit field in the first row to define the first range. Type 120 in the Start, 140 in Stop edit field and 3 in the Number edit field in the first row to define the second range.

Click Less to return to single range mode.


Reference frequency and maximum patch size in the model can be specified in the bottom part of the Frequency dialog.

To specify reference frequency, check the Set reference check box, and type in the value in the Value field. If the check box is left unchecked, the default reference frequency is Stop frequency.

To specify maximum patch size in the model, type in the desired value in wavelengths in the Max Patch Size field. The default is value is 2.

In the quick tour example, please leave the default values for Reference frequency and Max Patch Size.

Click OK. The dialog box closes.

3.2.3. Define the Structure Geometry

Any metallic structure is characterized by four different entities:

Nodes Wires

Plates

Junctions (nontrivial) Click Edit in the Main menu

bar. The Edit menu opens. Click Structure option in the

Edit menu. The Structure menu opens, as shown to the right.


3.2.3.1. Define Node Coordinates Any arbitrary point (node) is completely determined by its x, y, and z-

coordinates.

Click (or select Nodes in the Structure menu). The Nodes table opens.

Press Ins or drag and drop into the field. The default values for the first node are created.

To edit the first node n1 (0 m, 0.3 m, 0 m) type the number 0.3 in the y [m] edit field and press Enter. (Use the arrow keys or mouse to move to the desired edit field.)

Edit next five nodes in the same manner as the first node. The Nodes table looks as shown to the right.

3.2.3.2. Define the Start and End Nodes and Radii for a Wire

Wires are modeled by right-truncated cones. In general, a truncated cone is completely defined by its starting and ending point (node) and its starting and ending radii. Nodes on a wire are specified by their order numbers, given in the Nodes table.

Click (or select Wires in the Structure menu). The Wires table opens. Press Ins. The default values for the wire are created. Type the number 1 in the 1st Nodes edit field and press Enter to define the

first node of the wire. Edit 2nd wire node in the same manner as its 1st node.


Type the number 15 in the 1st Radii edit field and press Enter to define the first radius of the wire. Edit 2nd wire radius in the same manner as its 1st radius. The Wires table looks as shown above.

Ncs number of uniformly distributed points along wire in which the current distribution is listed and graphed.

3.2.3.3. Define the Corner Points of a Plate

A plate is completely determined by its four corner points (nodes) arbitrarily positioned in space. Their order numbers, given in the Nodes table, specifies the nodes for the plate. The order of the nodes in this specification can be almost arbitrary. The first and fourth nodes must belong to the plate diagonal.

Click (or select Plates in the Structure menu). The Plates table opens. Press Ins. The default values for the plate are created. Type number 3 in the 1st Nodes edit field and press Enter to define the first

corner node. Edit 2nd, 3rd, and 4th plate nodes in the same manner as 1st node. The Plates

table looks as shown above. Ncp, Ncs number of uniformly distributed points along p and s

coordinates in a grid of points where the current distribution is to be listed and graphed.

3.2.3.4. Define the Wire-to-Plate Junction Two wires having a common node and two plates having two common nodes

(that define a common edge of a plate) are automatically considered to be connected. However, the wire-to-plate junction must be specified for the structure under consideration. This junction is completely determined by the node on the wire situated on the plate. This junction node is specified by its order number, given in the Nodes table.

Click (or select Junctions in the Structure menu). The Junctions table opens.

Press Ins. The default values for the junction are created. (Each one is zero).


Type the number 1 in the 1. Nodes edit field and press Enter to define the junction at node 1. The Junctions table looks as shown below.

3.2.4. Define the Excitation for the Structure

In radiation problems, the generator is always connected to one node of a wire, and its reference direction is towards another node of the wire. A generator is completely determined by these two nodes and the complex voltage across them. The nodes associated with the generator are specified by their order numbers, given in the Nodes tables.

Click (or select Generators in the Excitation menu). The Generators table opens.

Type the number 1 in the 1st Nodes edit field to place generator at node 1.

Type the number 2 in the 2nd Nodes edit field to define the reference direction towards node 2. The Generators table looks as shown to the right.


3.2.5. Specify the Output Results

Calculation of output results is performed by using the options Current, Radiation and Near-Field, from the Output Results menu. In particular calculation of the current distribution along wires and plates can be specified in Wires and Plates tables as described in 3.2.3.2 and 3.2.3.3.

Click Output Results in the Edit menu. The Output Results menu is displayed, as shown to the right.

3.2.5.1. Specify the Directions for Radiation Calculations Far field is computed at one or more uniformly spaced angular directions.

Angular directions are specified by the spherical and -coordinates. The -coordinate is measured from the x-axis in the xOy-plane. The -coordinate is measured from the xOy-plane to the z-axis. Hence, it is the elevation angle. The space angle range is completely determined by the number of directions along the -coordinate, the start and stop -angles, the number of directions along the -coordinate, and the start and stop -angles.

Click Radiation in the Output Results menu. The Radiation Pattern dialog box opens.

Type the number 28 in the - Number of Directions edit field. Type the number 90 in the -Start Direction edit field. Type the number 360 in the -Stop Direction edit field.

Edit the -angle fields in the same manner as the -angle fields. The Radiation Pattern box looks as shown to the right.


3.2.5.2. Calculate the Currents along Wires and Plates Currents over the whole structure are calculated at a set of approximately

uniformly distributed points.

Click the Current in the Output Results menu. The Current menu opens. Choose density of points as Low, Middle, or High. Number of points along p and s coordinates can be defined manually by clicking the Set Ncp and Ncs.

3.2.5.3. Specify the Points for Near-Field Calculations WIPL-D evaluates the near-field (complex electric and magnetic field

vectors) at a specified set of uniformly spaced grid points. Click Near-Field in the Output

Results menu. The Near-Field dialog box opens.

Type the number 1 in the Number of X-coordinate edit field.

Type the number 150 in the Number of Y-coordinate edit field. Type numbers 800 and 800 in the Start Y-coordinate [mm] edit field and the Stop Y-coordinate [mm] edit field.

Type the number 50 in the Number of Z-coordinate edit field. Type number 650 in the Stop Z-coordinate [mm] edit field. The dialog box looks as shown to the right.


3.3. Show 3-D Drawing of the Metallic Structure

The Preview option shows a 3-D drawing of the edited structure. The structure can be colored, shaded, rotated, shifted, scaled etc. Its entities can be marked, numerated, located etc. Finally, different styles of graph can be configured. Use toolbars or shortcuts to perform these operations. The Preview window is shown to the left.

Click buttons or use the arrow keys to rotate the structure left, right, up or down, respectively.

Press and hold Ctrl key and click

buttons or arrow keys to move the structure left, right, up or down, respectively.

Click , , and to numerate all nodes, plates and all wires, respectively, as shown to the right above. Alternatively use the function keys F2, F3 and F4.

Click to mark all the nodes as shown to the right, or use Ctrl+N.


Click to mark the generator, as shown below to the left.

Click to mark the wire-to-plate junctions as shown below to the right.

3.4. Save the Input Data

When editing of the input data under the new project is finished, the project should be named and saved. Particularly, for the case when the upper status line shows WIPL-D: NEW, which means that input data have been edited under the new project, the Save As dialog box can be opened by clicking the Save icon.

Click (or select Save As in the File menu). The Save As dialog box opens.

The cursor is positioned in the File name edit field. Type in the name of the project, under which the current input data will be saved (e.g., the word FM-ANT). The Save As dialog box looks as shown to the right.

Click the Save button. The dialog box closes and the upper status line changes to WIPL-D: FM-ANT.


3.5. Run the Analysis

The running time of the analysis depends on the input data and the hardware of the computer. Most often, the analysis time at one frequency is less than a minute. (For example, Pentium-4 at 2.4 GHz needs 1 second to perform this example). Once the analysis is started, it can be interrupted by pressing Ctrl-C or Ctrl-Break.

Click (or select Run in the Run menu). The Run screen appears, and the analysis is started. The Run screen gives the basic data of analysis and shows the status of the analysis:

The end of the analysis is accompanied by a beep and the Run screen closes. At the same time the Main screen opens and the Run dialog box is displayed, giving elapsed time, as shown right. Press OK to close the Run dialog box.


3.6. List the Results

There are five groups of output data that can be listed: Input data, Y,Z,S, Currents (Electric and Magnetic), Radiation, and Near Field. The first group is formed after running the analysis and reading the input data. The other four groups represent the output results obtained after the analysis is finished.

Click List in the Output menu (Main menu bar). The List menu opens, as shown to the right.

Click Y,Z,S in the List menu. The List screen opens, as shown bellow.

The number of significant digits can be specified in the combo-box in the lower left part of the screen.

3.7. Print the Results

Output results, shown by the List screen are printed as follows:

Click Print Setup in the lower part of the List screen to specify printing properties.

Click Print to print the data shown at the List screen.

Click the Close button to close the List screen.


3.8. Make 2-D and 3-D Graphs of the Results

The Graph option gives 2-D and 3-D plots of the results. 3-D graphs can be rotated, magnified, and so forth. Select Graph in the Output menu and Graph menu opens as shown right.

Select Radiation in the Graph menu. The Graph screen appears.

Click three times. The graph is magnified.

Click six times. The graph is rotated vertically with respect to the screen.

Click . A polar graph of the antenna directive gain in the plane = 230 is displayed.

Click and hold until you hear the beep. The polar graph changes from the plane = 230 to the plane = 90, as shown below to the right.

Press the P button. The polar diagram changes to Cartesian as shown below to the left.


3.9. Print and Export Graphs

Output results, shown on the Graph screen can be printed or saved in the following formats: BMP, JPG, ASCII, Touchstone (for circuit parameters) and InfoView.

Click File in the Graph menu bar. The File menu opens as shown below to the left.

Select Print in the File menu to print the current graph. To export the graph in desired format, select Export to and choose the format.

Except in the case of InfoView the Save to Picture dialog box opens, as shown below to the right.

Type the name of the file in the File name edit field and click Save.

3.10. Use Existing Data

Once created and saved as a project, input data can be easily modified and used for new analysis. Instead of creating a new project in this tour, we could simply open an existing project and perform an analysis.

Click (or select Open in the File menu). The Open dialog box opens. Select Quick_Tour in the directories tree. Select Demo1.IWP, as shown

below to the right. Click Open. Demo1 project is loaded. The dialog box closes.


In case user wants to keep the project with all output results (e.g. under a new name), Save As with results dialog box should be used from the File menu.

3.11. Define the Problem (Composite Structure)

Any linear antenna, scatterer, or microwave device represents a combination of metallic and dielectric (material) bodies. In addition, metallic bodies can be considered to be composed of wires and plates. As in case of pure metallic structures, the main task is to create an adequate geometrical model of the structure and to define the excitation of the model.

To make an appropriate geometrical model of composite structure, the user should follow the same basic rules as with pure metallic structures. Note that the geometry of the dielectric surfaces is also approximated by quadrilaterals (bilinear surfaces). Since the geometry of both metallic and dielectric objects is defined by their surfaces, it is equally easy to model a metallic structure near a dielectric object as metallic structure immersed in the dielectric object. In this particular case, a metallic plate can be placed at the boundary surface of dielectric objects. Rest of the quick tour describes all three cases. Let us start with monopole antenna mounted on the plate, as in project FM-ANT.

Second example: Metallic structure immersed in truncated dielectric pyramid


For this problem, in addition to the data specified in the first example (see Section 3.1), we need the following additional eight nodes and six dielectric surfaces:

n7 ( 0.5, -0.8, 1 ) n8 ( -0.5, -0.8, 1 ) n9 ( 0.55, 0.8, 1 ) n10 ( -0.55, 0.8, 1 ) n11 ( 0.8, -1, -0.2 ) n12 ( -0.8, -1, -0.2 ) n13 ( 0.8, 1, -0.2 ) n14 ( -0.8, 1, -0.2 )

p2 ( n7, n8, n9, n10 ) p3 ( n7, n8, n11, n12 ) p4 ( n8, n10, n12, n14 ) p5 ( n10, n9, n14, n13 ) p6 ( n9, n7, n13, n11 ) p7 ( n11, n12, n13, n14 )

Third example: Metallic structure near truncated dielectric pyramid

This example is characterized in the same way as second example, except that each of eight new nodes, ni, i = 714, is shifted along x-axis for x=-2 m.

Fourth example: Dielectric prism covers upper plate surface


This example is defined by new four nodes and five dielectric surfaces: n7 ( 0.5, -0.8, 1 ) n8 ( -0.5, -0.8, 1 ) n9 ( 0.55, 0.8, 1 ) n10 ( -0.55, 0.8, 1 )

p2 ( n7, n8, n9, n10 ) p3 ( n3, n4, n7, n8 ) p4 ( n4, n6, n8, n10 ) p5 ( n6, n5, n10, n9 ) p6 ( n5, n3, n9, n7 )

Initially, in all these examples the electrical parameters of dielectric are the same as those of vacuum. Theoretically speaking, in these cases the computed results should be equal to the results obtained for the first example. However, while in the first example the antenna, which is metallic structure, radiates directly, in the second example the radiation is performed by dielectric surfaces. Due to numerical computations, these results will differ due to errors in the various approximations. However, the small differences in the results indicate that the geometrical model of the composite structure as constructed in the second example is quite satisfactory.

3.12. Edit the Input Data (Composite Structures)

As in the case of the metallic structures, all input data is edited through the Edit menu (See Section 3.2). To illustrate editing data, let us start with the FM-ANT project. For specifying a composite structure we need to modify data only in Structure geometry.

3.12.1. Define the Geometry of the Composite Structures

As in the case of the metallic structures, the group of data called Structure geometry is edited through the Structure submenu, as explained in Section 3.2.1. However, to define composite structures, we need to use an additional entity, called Domain. Note that in Section 3.2.1 WIPL-D was configured for metallic structures. In that case, the Domain option was inactive. To make this option active, configure WIPL-D for dielectric structures, as explained in the beginning of this chapter.

Edit nodes in the same way as in the case of metallic structures. In the following section, we show how to edit domains, wires, and plates.


3.12.1.1. Define Domains for the Composite Structures The domain consists of all bodies made of the same material. The electric

properties of these materials are characterized by:

Complex relative permittivity, ir j += Complex relative permeability, ir j += Conductivity, (in S/m)

Specifically: The 0th domain consists of all bodies made of perfect electric conductor

(PEC). The first domain is always the outer space filled by vacuum. Boundary surfaces of domains are defined by right-truncated cones and

bilinear surfaces.

Click . (or Domains in the Structure menu). The Domains table opens. It contains one row that defines the electrical parameters of the 1st domain (vacuum).

Press Ins. The default values for the domain that corresponds to vacuum are created. For the moment, let us keep the default values for the second domain.

3.12.1.2. Define the Domain to Which the Wire Belongs

The definition of wires is done similarly as for metallic structures. In addition, each wire should have a domain specification. A wire belongs to one domain only. A wire is always immersed in that domain.

Click . The Wires table opens. It contains one row that defines one wire. The Domain edit field shows number 1, which means that the wire is immersed into the outer domain. In the case of the 2nd and 4th examples, it should be immersed into a truncated dielectric pyramid, which belongs to the


2nd domain. Type the number 2 in the Domain edit field and press Enter. The Wires table looks as shown above.

3.12.1.3. Define Domains of Metallic and Dielectric Plates The geometry of dielectric bodies is modeled in the same way as for metallic

structures (i.e., by bilinear surfaces). Hence, these surfaces are also called plates. Metallic plates placed at the boundary surface of two domains cannot be treated as a single current sheet. Therefore, there are three types of plates:

A basic metallic plate is always immersed in one domain only. It is accompanied by a single electric current sheet.

Composite metallic plate is placed between two domains. It is accompanied by a double electric current sheet, each immersed in one of the neighboring domains.

A dielectric plate represents the boundary surface between two domains. It is accompanied by equivalent electric and magnetic current sheets (taken with a plus sign in the domain with a lower order number, and a minus sign in the domain with a higher order number). Plates are edited in same way as for metallic structures. In addition, for each

plate it should be defined to which domains it belongs, according to the following rules.

Type of plate Domains 1st 2nd

Basic metallic (immersed into domain i only) i 0 Composite metallic (placed at interface of domains i and j)

- i - j Dielectric (boundary surface between domains i and j) i j

Click . The Plates table opens. It contains one row that defines one plate. The table is as shown in 3.2.3.3, except that the 1st and 2nd Domain edit fields are now visible. The 1st Domain edit field shows 1, and the 2nd Domain edit field shows 0, which means that the plate is immersed into the outer vacuum domain (first domain). 2nd example: The metallic plate should be immersed into a dielectric pyramid, which

belongs to the second domain: Type the number 2 in the 1st Domain edit field and press Enter. Type the

number 0 in the 2nd Domain edit field and press Enter. Similarly, for each dielectric plate:


Type the number 1 in the 1st Domain edit field and press Enter. Type the number 2 in the 2nd Domain edit field and press Enter. The Plates table looks as shown bellow to the left. 3rd example: The metallic plate is of a basic type and is immersed into a vacuum (first

domain). Therefore, for the metallic plate: Type the number 1 in the 1st Domain edit field and press Enter. Type the

number 0 in the 2nd Domain edit field and press Enter. The Plates table looks as shown below middle. 4th example: The metallic plate is of a composite type and is placed at the boundary

surface between a dielectric pyramid and vacuum (first and second domains). Therefore for the metallic plate:

Type the number -1 in the 1st Domain edit field and press Enter. Type the number -2 in the 2nd Domain edit field and press Enter. The Plates table looks as shown below to the right.

3.13. Show a 3-D Drawing of the Composite Structure

The Preview option for composite structures is the same as for metallic structures. However, in this case, it is very important to examine to which domains the plates belong. This is done by coloring the plates. The color of the plate depends on the domains to which the plate belongs. By default, all domains are visible, and the plate is marked with the color of the domain with the lowest order number. If some of domains are specified as invisible, the plate is marked


with the color of the visible domain with the lowest order number. To illustrate this, open Demo3 project.

Click . The Visible Domains dialog box opens. Type 0 in the edit field and click OK. (Only the 0th domain is visible. The metallic plate is colored in blue).

Click . The Visible Domains dialog box is displayed. Type 1 in the edit field and click OK. (Only the 1st domain is visible. All plates are colored in red.)

Click . The Visible Domains dialog box opens. Type 2 in the edit field and click OK. (Only 2nd domain is visible. The dielectric plates are colored in yellow).

Click . The Visible Domains dialog box opens. Type 1 in the edit field, click on Complement, and click OK. (All domains, except the 1st one, are visible.).


3.14. Compare Output Results for Different Projects

Output results obtained under different projects can be overlaid. Open the project Demo1, and compare its results with those of Demo2.

Select Radiation in the Graph menu.

Click . A polar graph of antenna directive gain in the plane = 230 is obtained.

Select Overlay in the Graph menu bar. The Overlay dialog box opens.

Click Demo1 in the Projects list and click . Demo1 appears in the Overlay list, as shown above.

Click the Overlay button and click the Close button. The Overlay dialog box closes. The graphs from projects Demo1 and Demo2 are overlaid.

Click and change frequency to 100 MHz, as shown below to the left. Click Overlay button once again and check Group. Graph looks as shown

below to the right.

WIPL-D Basic Theory 4-1

4. Basic Theory

In this chapter, the basic theory of electromagnetic modeling applied in WIPL-D is outlined. The reader can skip this section and proceed directly to Chapter 5, as WIPL-D can be used without knowledge of the analysis method.

Parts of the theory are mostly published in [1-29]. The reader may consult the references mentioned for additional details. Some parts of the theory applied are developed especially

Documents

WIPL-D User's Manual