A Graphical User Interface
NEC-BSC Workbench V4.1
G. F. Paynter
and R. J. Marhefka
The
ElectroScience Laboratory
Tel: (614)292-5752
Fax: (614)292-7297
E-mail: marhefka.1@osu.edu
July 1998
The NEC - Basic Scattering Code (NEC-BSC) has been
used for over 20 years for the analysis of high frequency antenna performance
on complicated structures such as ships, aircraft, and missiles. The user interface to the program consists of
an input file that contains commands and data.
This classical mechanism is flexible, transportable and efficient. In
contrast, modern graphical user interfaces provide very high levels of user
interaction at the expense of transportability.
The optimal solution is to retain the classical interface and create a
graphical user interface to assist the user in manipulating the input command
file. The almost universal acceptance of
Microsoft Windows makes it the natural choice for implementing a graphical user
interface. Version 4 is written for
Windows 9x and 2000 or above.
The NEC-BSC Workbench™ is a
windows based environment for creating and manipulating input files for
NEC-BSC. The user can open an existing
file containing NEC-BSC commands or create new files. The input commands are displayed in an edit
window, and the actual geometry is displayed in separate wire frame views. Any number of wire frame views can be
created, allowing simultaneous viewing of the geometry from several
angles. As the user makes changes to the
input file, these changes are reflected in the wire frame views. By or by double-clicking on a specific
command in the input file or on a geometry item in one of the wire frame views,
the user can load the entire command into a dialog box and thus obtain very
high levels of user interaction. Command
blocks can be easily commented out of or back into the input file via a
right-click context menu. Pattern cuts
can be visualized in the wire frame view, and sources and/or receivers may be
‘flown’ through pattern cut loci to help visualize source/receiver
orientations. In the NEC-BSC, up to
three coordinate systems can be associated with a particular geometry
object. The ‘reference’ coordinate
system is common to all objects, the ‘local’ coordinate system reflects the
result of any RR (Relative Rotate) or RT (Rotate/Translate) commands, and some
complex objects have an internal ‘object’ coordinate system that defines their
location & orientation relative to the object’s center. The workbench allows the user to enable or
disable display of the different coordinate systems on an object by object
basis via right-click context menus
In a new version of the NEC-BSC, an option to output
the ray paths and field information is implemented. The NEC-BSC Workbench can read these files
and display the ray paths superimposed on the wire frame views of the geometry. For complicated problems, where the number of
rays is large, the Workbench provides various filters for selecting which rays
will be drawn. Rays can be filtered
based on the number of interactions or by relative power. The Workbench also supports OLE2 drag and
drop for moving rays from one wire frame view to another. It can also read .OAA files generated by the
NEC-BSC and plot the fields in rectangular form.
The NEC-BSC Workbench Version 4.1 contains full
on-line help, including a command reference section for all NEC-BSC commands.
NOTE: Version 4 of the NEC-BSC Workbench was
intended as the graphical companion to Version 4. However, with some limitations it can also be
used with NEC-BSC Version 3.4. The
limitations have to do with the fact that Version 3.4 does not have all the
features of Version 4. The present
version does not completely support all the new features of NEC-BSC V4.2 or
above.