G G |
G G |
G G |
G G |
G G |
G G |
G | G |
G | G |
G | G H
G v <--g--><--w--><---s---><--w--><--g--> G |
GGGGGGGGGG ccccccc ccccccc GGGGGGGG |
G.|t.Dielectric, permittivity=Er2.......h.............G |
G.|...(3.7 for FR4 PCB).................|.............G |
The parameters 'W' and 'H' and the inner dimensions of the a metal enclosure. These will generall be quite large compared to the dimensions of the the PC - the diagram above is not to scale. The gap between the two coupled lines is s, the width of the coupled lines is w and the spacing between the edges of the coupled lines and the groundplane on the top is g. Often, the upper groundplane is not close to the coupled lines, in which case g will be quite large. The thickness of the dielectic is h. Note that he is just the dielectric, and does not include the thichkness of the copper on the double-sided PCB. The thickness of copper on the top layer is t. It is immaterial what the thickkness of the lower layer is. The relative permittivity above the dielectric is normally 1, but the relative permittivity of the dielectric material will need to be either pre-defined or defined on the command lines. See the section colours below for more information on dielectrics.
The bitmap is printed to the file specified as the last argument
The bitmaps produced by create_bmp_for_microstrip_coupler are 24-bit bit colour bitmaps, as are required by atlc.
The permittivities of the bitmap, set by 'Er1' and 'Er2', determine the colours in the bitmap. If Er1 or Er2 is 1.0, 1.0006, 2.1, 2.2, 2.33, 2.5, 3.3, 3.335, 3.7, 4.8, 10.2 or 100, then the colour corresponding to that permittivity will be set according to the colours defined in COLOURS below. If Er1 is not one of those permittivities, the region of permittivity Er1 will be set to the colour 0xCAFF00. If Er2 is not one of those values, then the region of the image will be set to the colour 0xAC82AC. The program atlc does not know what these two permittivites are, so they atlc, must be told with the comand line option -d, as in example 4 below.
Causes create_bmp_for_microstrip_coupler to print some data to stderr. Note, nothing extra goes to standard output, as that is expected to be redirected to a bitmap file.
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
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 0x0000FF 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)
L. 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 0x696969 as Er=6.15 (duroid 6006)
L. gray 240,240,240 or 0xDCDCDC as Er=10.2 (duroid 6010)
D. orange 213,160,067 or 0xD5A04D as Er=100.0 (mainly for test purposes)
In the first example, there is just an air dielectric, so Er1=Er2=1.0. The inner of 1x1 inches (or mm, miles etc) is placed centrally in an outer with dimensions 3 x 3 inches.
The exact place where the dielectric starts (a) and its width (d) are unimportant, but they must still be entered.
% create_bmp_for_microstrip_coupler 3 3 1 1 1 1 1 1 > ex1.bmp
% atlc ex1.bmp
In this second example, an inner of 15.0 mm x 0.5 mm is surrounded by an outer with internal dimensions of 61.5 x 20.1 mm. There is a material with permittivity 2.1 (Er of PTFE) below the inner conductor. The output from create_bmp_for_microstrip_coupler is sent to a file ex1.bmp, which is then processed by atlc
% create_bmp_for_microstrip_coupler 61.5 20.1 5 22 0.5 50 15 5 1.0 2.1 > ex2.bmp
% atlc ex2.bmp
In example 3, the bitmap is made larger, to increase accuracy, but
otherwise this is identical to the second example.
% create_bmp_for_microstrip_coupler -b7 61.5 20.1 5 22 0.5 50 15 5 1.0 2.1 > ex3.bmp
% atlc ex3.bmp
In the fourth example, materials with permittivites 2.78 and 7.89 are used. While there is no change in how to use create_bmp_for_microstrip_coupler, since these permittivities are not known, we must tell atlc what they are. % create_bmp_for_microstrip_coupler 61 20 1 4 22 0.5 50 15 5 2.78 7.89 > ex5.bmp % atlc -d CAFF00=2.78 -d AC82AC=7.89 ex5.bmp In the sixth and final example, the -v option is used to print some extra data to stderr from create_bmp_for_microstrip_coupler.
http://atlc.sourceforge.net - Home page
http://sourceforge.net/projects/atlc - 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