atlc - an Arbitrary Transmission Line Calculator


     atlc  [-C] [-s] [-S] [-v] [-c  cutoff]  [-d  rrggbb=Er]  [-i
     factor]  [-i  prefix] [-t threads] [-r rate_multiplier] bit-


     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 documen-
     tation - even spelling errors and typos, please let me know.


     atlc is a finite difference program that is used  to  calcu-
     late  the properties of a two-conductor electrical transmis-
     sion line of arbitrary cross section. It  is  used  whenever
     there are no analytical formula known, yet you still require
     an answer. It can calculate:
        The impedance Zo  (in Ohms)
        The capacitance per unit length (pF/m)
        The inductance per unit length (nF/m)
        The velocity of propagation v (m/s)
        The velocity factor, v/c, which is dimensionless.

     A bitmap file (usually with the extension .bmp or  .BMP)  is
     drawn  in  a  graphics  package  such as Gimp available from The bitmap file must be saved as a  24-
     bit  (16,777,216 colour) uncompqessed file. The colours used
     in the bitmap indicate whether the  region  is  a  conductor
     (pure  red,  pure  green or pure blue) or a dielectric (any-
     thing else). Pure white is assumed to be  a  vacuum  dielec-
     tric, but other colours have different meanings. See COLOURS
     below for precise definitions of the colours.


     print copyright, licensing and copying information.
     Skip writing the Ex, Ey, E, V, U and Er bitmap (.bmp)  files
     Skip writing the Ex, Ey, E, V, U and Er binary (.bin) files
     makes the output more verbose/talkative.
     -c cutoff
     Sets the convergence criteria of the finite difference  pro-
     gram. The default is 0.0001, meaning two separate iterations
     must be within 01% for the program to stop  iterating.  Set-
     ting  to  a smaller positive number gives more accuracy, but
     takes longer.

     -d rrggbb=Er
     is used to indicate the colour 0xrrggbb  in  the  bitmap  is
     used  to represent a material with permittivity Er. See also
     COLOURS below

     -i factor
     is used to lighten or darken the .bmp electric field profile
     images  produced  by  atlc.  Set  factor  >  2 to lighten or
     between 1 and 2 to darken.

     -r ratemultiplier
     Sets the parameter 'r' used internally  when  computing  the
     voltage  at  a point w,h.  The default, which is (as of ver-
     sion 3.0.0) 1.95, results in what is believed to be  optimal
     results.  Setting to 1.0 will avoid the use of the fast con-
     vergence method, which is generally not a good idea.

     -p prefix
     Adds 'prefix', which is usually a directory name,  in  front
     of the output files.


     The 24-bitmaps that  atlc  uses  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, turquiose,  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 reconised
     by atlc, or you must define it with a  command  line  option
     (see OPTIONS).
     red    = 255,000,000 or 0xFF0000 is the live conductor.
     green  = 000,255,000 or 0x00FF00 is the grounded conductor.
     blue   = 000,000,255 or 0x0000FF is the negative conductor

     All bitmaps must have the live (red)  and  grounded  (green)
     conductor. The blue conductor is used to indicate a negative
     conductor, is needed when the program  is  used  to  analyse
     directional couplers.

     The following dielectrics are reconised by atlc:

     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)
     L. yellow 223,247,136 or 0xDFF788 as Er=3.7    (FR4 PCB)
     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)


     Here are a few examples of the use of atlc. Again,  see  the
     html documentation in atlc-X.Y.Z9ocsl-docs, the documentation
     on         your         system         (normally          at
     /usr/local/share/atlc/docs/html-docs/index.html  ) or online
     at for examples.

     ex_1 % atlc coax2.bmp
     This is a simple example (ex_1), in which the geometry of  a
     transmission  line is defined in coax2.bmp. In this example,
     only the predefined dielectrics (Er =1.0, 1.0006, 2.1,  2.2,
     2.33,  2.5,  3.3,  3.335, 3.7, 4.8, 6.15 or 10.2) could have
     been used in the bitmap, which would have been done with one
     of  13  different colours. white (0xFFFFFF) for Er=1.0, pink
     (0xFFCACA) for 1.0006 etc.   No  other  colour  (dielectric)
     could have been used, since it was not specified with the -d

     ex_2 % atlc -d f9e77d=2.43 somefile.bmp
     In ex_2, a dielectric with Er=2.43 was wanted. A colour with
     the  RGB  values  of  0xF9E7&d was used. The -d option tells
     atlc what Er this colour refers to.

     ex_3 % atlc -v coax2.bmp
     In ex_3, atlc has been instructed to print  the  results  of
     intermediate  calculations  to  stdout.   Normally, only the
     final result is printed. Using -vv even more information may
     be produced, but this is really of only use to the developer
     of the project.


        Original bitmap file. Must be 24-bit colour uncompressed.
        X-component of E-field as a bitmap. Red=+dV/dx,  blue  =-
        y-component of E-field as a bitmap. Red=+y, blue =-y
        E-field, as E=sqrt(Ex^2+Ey^2).
        Voltage as a bitmap, red= positive, blue =negative.
        Bitmap showing the permittivity as a  grayscale.  Lighter
     is a higher

     In addition to the bitmaps, the data is also saved in binary

     All the saved binary files (.bin's) are saved  as  a  double
     precision number for each of the pixels. The first double is
     the top left, the last the bottom  right.  If  the  original
     image  has width W and height H, the saved binary files will
     be W-1 by H-1.

     All the saved bitmap files  are  24-bit  uncompressed,  just
     like the input files.


     atlc(1)                       create_bmp_for_circ_in_circ(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

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