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create_bmp_for_circ_in_circ(1) Dr. David Kirkby create_bmp_for_circ_in_circ(1)


create_bmp_for_rect_cen_in_rect - bitmap generator for rectangular conductor inside rectangular conductor (part of atlc)


create_bmp_for_rect_cen_in_rect [options... ] W H w h Er outfile.bmp


This man page is not a complete set of documentation - the complexity of the atlc project makes man pages not an ideal way to document it, although out of completeness, man pages are produced. The best documentation that was current at the time the version was produced should be found on your hard drive, usually at
although it might be elsewhere if your system administrator chose to install the package elsewhere. Sometimes, errors are corrected in the documentation and placed at before a new release of atlc is released. Please, if you notice a problem with the documentation - even spelling errors and typos, please let me know.


create_bmp_for_rect_cen_in_rect is a pre-processor for atlc, the finite difference program that is used to calculate the properties of a two-conductor electrical transmission line of arbitrary cross section. The program create_bmp_for_rect_cen_in_rect is used as a fast way of generating bitmaps (there is no need to use a graphics program), for a rectangular conductor placed centrally inside another rectangular conductor, like this:

----------------------------------------------------- ^
| | |
| Dielectric, permittivity=Er | |
| | |
| | |
| | |
| <----------w-----------> | |
| ------------------------ ^ | |
| | | | | |
| | Metallic conductor | | | H
| | conductor (must be | h | |
| | in the centre) | | | |
| | | | | |
| ------------------------ ^ | |
| | |
| | |
| | |
| | |
| | |
| | |
----------------------------------------------------- |

The parameters 'W' and 'H' and the inner dimensions of the outer conductor. The outer dimensions of the inner conductor are 'w' and 'h'. The inner conductor is assumed be be placed centrally inside the outer conductor. The spaced between the two conductors is filled with a dielectric of relative permittivity Er

The bitmaps produced by create_bmp_for_rect_cen_in_rect are 24-bit bit colour bitmaps, as required by atlc.

The permittivity of the bitmap, set by 'Er', determine the colours in the bitmap. If Er is 1.0, 2.1, 2.2, 2.33, 2.5, 3.3, 3.335, 4.8 or 10.2, then the colour corresponding to that permittivity will be set according to the colours defined in COLOURS below. If Er is not one of those permittivities, the region of permittivity Er will be set to the colour 0xCAFF00. The program atlc does not know what these permittivites are, so they atlc, must be told with the comand line option -d, as in example 4 below.


-b bitmapsize
is used to set the size of the bitmap, and so the accuracy to which atlc is able to calculate the transmission line's properties. The default value for 'bitmapsize' is normally 4, although this is set at compile time. The value can be set anywhere from 1 to 15, but more than 8 is probably not sensible.

-f outfile
Set the output filename. By default, the bitmap is sent to stdout, but it *must* be sent to a file, with this option, or as described above.

Causes create_bmp_for_rect_cen_in_rect to print some data to stdout.


The 24-bit bitmaps that atlc expects, have 8 bits assigned to represent the amount of red, 8 for blue and 8 for green. Hence there are 256 levels of red, green and blue, making a total of 256*256*256=16777216 colours. Every one of the possible 16777216 colours can be defined precisely by the stating the exact amount of red, green and blue, as in:

red = 255,000,000 or 0xff0000
green = 000,255,000 or 0x00ff00
blue = 000,000,255 or 0x0000ff
black = 000,000,000 or 0x000000
white = 255,255,255 or 0xffffff
Brown = 255,000,255 or 0xff00ff
gray = 142,142,142 or 0x8e8e8e

Some colours, such as pink, turquoise, sandy, brown, gray etc may mean slightly different things to different people. This is not so with atlc, as the program expects the colours below to be EXACTLY defined as given. Whether you feel the colour is sandy or yellow is up to you, but if you use it in your bitmap, then it either needs to be a colour recognised by atlc, or you must define it with a command line option (see OPTIONS and example 5 below).
The following conductors are recognised by atlc:
red = 255,000,000 or 0xff0000 is the live conductor.
green = 000,255,000 or 0x00ff00 is the grounded conductor.
blue = 000,000,000 or 0x000000 is the negative conductor

All bitmaps must have the live (red) and grounded (green) conductor. The blue conductor is not currently supported, but it will be used to indicate a negative conductor, which will be needed if/when the program gets extended to analyse directional couplers.

The following dielectrics are recognised by atlc and so are produced by create_bmp_for_rect_cen_in_rect.

white 255,255,255 or 0xFFFFFF as Er=1.0 (vacuum)
pink 255,202,202 or 0xFFCACA as Er=1.0006 (air)
light blue 130,052,255 or 0x8235Ef as Er=2.1 (PTFE)
Mid gray 142,242,142 or 0x8E8E8E as Er=2.2 (duroid 5880)
mauve 255.000,255 or 0xFF00FF as Er=2.33 (polyethylene) yellow 255,255,000 or 0xFFFF00 as Er=2.5 (polystyrene)
sandy 239,203,027 or 0xEFCC1A as Er=3.3 (PVC)
brown 188,127,096 or 0xBC7F60 as Er=3.335 (epoxy resin)
Turquoise 026,239,179 or 0x1AEFB3 as Er=4.8 (glass PCB)
Dark gray 142,142,142 or ox696969 as Er=6.15 (duroid 6006)
L. gray 240,240,240 or 0xDCDCDC as Er=10.2 (duroid 6010)
D. orange 213,130,067 or 0xD5A04D as Er=100.0 (mainly for test purposes)
If the permittivity is one not in the above list, then those parts of the image with Er will be set to 0xCAFF00.


Here are a few examples of the use of create_bmp_for_rect_cen_in_rect. Again, see the html documentation in atlc-X.Y.Z/docs/html-doc/index.html for more examples.

1) In the first example, there is just a vacuum dielectric, so Er=1.0. The inner of 1x1 inches (or mm, miles etc) is placed centrally in an outer with dimensions 3.3 x 3.9 inches.

% create_bmp_for_rect_cen_in_rect 3.3 3.9 1 1 1 > 1.bmp
% atlc 1.bmp

2) In this second example, an inner of 15.0 mm x 5.0 mm is surrounded by an outer with internal dimensions of 71.5 x 60.0 mm. There is a material with permittivity 2.1 (Er of PTFE) around the inner conductor. The output from create_bmp_for_rect_cen_in_rect is sent to a file 2.bmp, which is then processed by atlc

% create_bmp_for_rect_cen_in_rect 71.5 60.0 15.0 5.0 2.1 > 2.bmp
% atlc 2.bmp

3) In example 3, the bitmap is made larger, to increase accuracy, but otherwise this is identical to the second example. % create_bmp_for_rect_cen_in_rect -b7 71.5 60 15 5 2.1 > 3.bmp
% atlc 3.bmp

In the fourth example, instead of re-directing create_bmp_for_rect_cen_in_rect's output to a file with the > sign, it is done using the -f option.
% create_bmp_for_rect_cen_in_rect -f 4.bmp 61.5 28.1 5 22 2.1
% atlc 4.bmp


atlc(1) create_bmp_for_circ_in_circ(1) create_bmp_for_circ_in_rect(1) create_bmp_for_microstrip_coupler(1) create_bmp_for_rect_cen_in_rect_coupler(1) create_bmp_for_rect_in_circ(1) create_bmp_for_rect_in_rect(1) create_bmp_for_stripline_coupler(1) create_bmp_for_symmetrical_stripline(1) design_coupler(1) find_optimal_dimensions_for_microstrip_coupler(1) readbin(1) - Home page - Download area
atlc-X.Y.Z/docs/html-docs/index.html - HTML docs
atlc-X.Y.Z/docs/qex-december-1996/atlc.pdf - theory paper
atlc-X.Y.Z/examples - examples

atlc-4.4.2 10th Sept 2003