NAME
create_bmp_for_microstrip_coupler - bitmap generator for
microstrip coupler (part of atlc)
SYNOPSIS
create_bmp_for_microstrip_coupler [-b bmp_size] [-v] w s g h
t Er1 Er2 filename
WARNING
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
/usr/local/share/atlc/docs/html-docs/index.html
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
http://atlc.sourceforge.net/ before a new release of atlc is
released. Please, if you notice a problem with the documen-
tation - even spelling errors and typos, please let me know.
DESCRIPTION
create_bmp_for_microstrip_coupler is a pre-processor for
atlc, part of atlc properties of a two and three conductor
electrical transmission line of arbitrary cross section. The
program create_bmp_for_microstrip_coupler is used as a fast
way of generating bitmaps (there is no need to use a graph-
ics program), for microstrip couplers. Hence if the dimen-
sions of a coupler are known the odd mode, even mode, dif-
ferential mode and common mode impedances can be found. If
you know what impedances you require and want to find the
dimentions, then use
find_optimal_dimensions_for_microstrip_coupler instead. This
makes repeated calls to create_bmp_for_microstrip_coupler.
The structure for which bitmaps are generated by
create_bmp_for_microstrip_coupler is shown below.
GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG ^
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 |
GGGGGGGGGG.......ccccccc.........ccccccc.......GGGGGGGG |
G.^.....................................^.............G |
G.|.....................................|.............G |
G.|t.Dielectric, permittivity=Er2.......h.............G |
G.|...(3.7 for FR4 PCB).................|.............G |
G.......................................V.............G |
GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG |
GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG. v
<------------------------W---------------------------->
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 per-
mittivity 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.
OPTIONS
-C Causes create_bmp_for_microstrip_coupler to print copy-
right and licensing information. -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.
-v
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.
COLOURS
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 pos-
sible 16777216 colours can be defined precisely by the stat-
ing 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).
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)
EXAMPLES
Here are a few examples of the use of
create_bmp_for_microstrip_coupler. Again, see the html docu-
mentation in atlc-X.Y.Z/docs/html-docs/index.html for more
examples.
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 sur-
rounded 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 accu-
racy, 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 permittivi-
ties 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.
SEE ALSO
atlc(1) create_bmp_for_circ_in_circ(1)
create_bmp_for_circ_in_rect(1)
create_bmp_for_rect_cen_in_rect(1)
create_bmp_for_rect_cen_in_rect_coupler(1)
create_bmp_for_rect_in_circ(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)
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
Man(1) output converted with
man2html