0. A floss Visual ElectroMagnetics Simulator for 3D Antennas
Antennas Research Group / Democritus University of Thrace
Christos Koutsos, Nikolitsa Yannopoulou and Petros Zimourtopoulos
VEMSA3D
A floss Visual ElectroMagnetics Simulator for 3D Antennas
Starting Frame
33rd TSP 2010

1. ThinWire 1980 RichWire 1990 VEMSA3D - Ancestors : 1/2
Simulation is performed by RichWire, which has been written again entirely in C++. RichWire is based on J.H.Richmond’s THINWIRE FORTRAN computer program and uses the Method of Moments.

2. WWW Virtual Reality 1995 RadPat4w 2000 VEMSA3D - Ancestors : 2/2
Simulation is performed by RichWire, which has been written again entirely in C++. RichWire is based on J.H.Richmond’s THINWIRE FORTRAN computer program and uses the Method of Moments.

3. VEMSA3D - The Starting Window
Main Window is used for antenna design. Here we see a structure resembling an airplane. Antenna structure is formed by basic elements: Nodes, Wires, Generators and Loads

4. VEMSA3D - Menus and Dialog Boxes
VEMSA3D helps design the antenna geometry and simulate it. Simulation results include Currents on the antenna wires, E and U radiation patterns in 3D and 2D, Directivity and Gain, Input and Output power, Input impedances, VSWR.

5. 2D and 3D E - U Radiation Patterns
VEMSA3D - Simulation Results : 1/2
2D and 3D E - U Radiation Patterns
Characteristic example: Half-wave dipole, sinusoidal distribution, E and U 3D and 2D radiation patterns
Industrial Standard The Half-wave Dipole : 9 modes

6. VEMSA3D - Simulation Results : 2/2
Typical commercial TV UHF Antenna: geometry, 3D and 2D U radiation patterns
Commercial Antenna
HUF TV : 723 modes

7. Experimental Antenna Array of 2 dipoles : 73 modes
VEMSA3D - Comparison - Simulation Results with Measurements : 1/4
Array of 2 dipoles with transmission line: photo, geometry, 3D and 2D U radiation patterns with analytical predictions and measurements
Experimental Antenna
Array of 2 dipoles : 73 modes

8. Amateur Antenna "Hentenna" : 109 modes
VEMSA3D - Comparison - Simulation Results with Measurements : 2/4
Hentenna: photo, geometry, 3D and 2D U radiation patterns with measurements
Amateur Antenna "Hentenna" : 109 modes

9. Experimental Antenna Monopole over a counterpoise : 167 modes
VEMSA3D - Comparison - Simulation Results with Measurements : 3/4
Monopole over printed counterpoise with 4 radials: photo, geometry, 3D and 2D U radiation patterns, theta and phi components with the corresponding measurements
Experimental Antenna
Monopole over a counterpoise : 167 modes

10. VEMSA3D - Comparison - Simulation Results with Measurements : 4/4
Monopole over printed counterpoise with 16 radials w/wo grounded disc: photo, geometry, 3D and 2D U radiation patterns with the corresponding measurements
Experimental Antenna A Monopole over a Counterpoise over a Wired-Disk : 2,594 modes

11. VEMSA3D - Comparison with Freeware 4NEC2X : 1/2
Jet airplane: geometry, 3D radiation patterns, comparison with 4NEC2 the other freely available electromagnetic simulator but not FLOSS
Antenna on Airplane
VEMSA3D : 391 modes

12. Horn with Bow-Tie feeder, by Pittra and Raida, 2010
VEMSA3D - Comparison with Freeware 4NEC2X : 2/2
Horn antenna with bow-tie feeder: geometry with fewer segments for comparison with 4NEC2 (1500 max)
Horn with Bow-Tie feeder, by Pittra and Raida, 2010
1,370 modes from 1,206 segments =< 1,500 max segments of 4NEC2X

13. Old Version 1.0 Short Cross Antenna
VEMSA3D : Improvements
Old Version 1.0
Short Cross Antenna
New version
Short Crossed Dipole: E radiation pattern theta and phi components change from version 1.0 to 1.1
It is the simplest antenna with the simplest two sources of 1 Volt value and 0 degrees phase. VEMSA3D accepts more than one source.
Total Pattern
Theta-Pattern
Phi-Pattern

14. VEMSA3D is developed in C++ as /F/L/O/S/S/
VEMSA3D - Unique Characteristics : 1/3
VEMSA3D is developed in C++ as /F/L/O/S/S/
Free Libre Open Source Software
Backend
RichWire
Public Domain
GUI
GNU GPL
Graphics
Free
VEMSA3D is FLOSS and is licensed under the GNU General Public Licence.
It is written in C++ and uses the wxWidgets library for the GUI, the OpenGL API for 3D graphics and the RichWire computer program as backend for simulation.

15. Horn with Bow-Tie feeder, by Pitra and Raida, 2010
VEMSA3D - Unique Characteristics : 2/3
Horn antenna with bow-tie feeder: geometry designed for Input Impedance ~50 [Ohm]
Horn with Bow-Tie feeder, by Pitra and Raida, 2010
3,266 points, 4,362 segments => 5,458 modes

16. VEMSA3D - Unique Characteristics : 3/3
Horn antenna with bow-tie feeder: Full geometry radiation pattern and view of currents on the antenna

17. VEMSA3D - Main Conclusions
- is only limited by computing resources and time,
- is Free Libre Open Source Software Code for everybody,
- is expandable by anyone,
- surpasses any restriction imposed by any authority
on modeling points, segments or modes
of any other Visual Electromagnetics Antenna Simulator,
either freeware or commercialware.
Horn antenna with bow-tie feeder: geometry designed for Input Impedance ~50 [Ohm]

18. VEMSA3D Source Code, Updated Material
33rd TSP 2010
VEMSA3D Source Code, Updated Material
code.google.com/p/rga/
Finish
Thank you for your attention
Antennas Research Group, Palaia Morsini, Xanthi, Thrace, Hellas, EU