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atlc(1)			    General Commands Manual		       atlc(1)

       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] bitmapfile

       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	 docu-
       mentation  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.

       atlc is a finite	difference program that	is used	to calculate the prop-
       erties  of  a  two-conductor  electrical	transmission 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 (anything
       else). Pure white is assumed to	be  a  vacuum  dielectric,  but	 other
       colours have different meanings.	 See COLOURS below for precise defini-
       tions of	the colours.

       print copyright,	licensing and copying information.
       Skip writing the	Ex, Ey,	E, V, U	and Er bitmap (.bmp) files -S
       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 program. The de-
       fault is	0.0001,	meaning	two separate iterations	must be	within 01% for
       the program to stop iterating. Setting 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	repre-
       sent 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

       -r ratemultiplier
       Sets the	parameter 'r' used internally when computing the voltage at  a
       point  w,h.   The default, which	is (as of version 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 convergence method, which is generally not	a good

       -p prefix
       Adds 'prefix', which is usually a directory name, in front of the  out-
       put 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	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, 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 re-
       conised by atlc,	or you must define it with a command line option  (see
       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 pur-

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

       ex_1 % atlc coax2.bmp
       This  is	 a simple example (ex_1), in which the geometry	of a transmis-
       sion 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 option.

       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 =-dV/dx
	  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 files.

       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

       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(1)
       create_bmp_for_rect_cen_in_rect_coupler(1)			  cre-
       ate_bmp_for_rect_in_circ(1)     create_bmp_for_rect_in_rect(1)	  cre-
       ate_bmp_for_stripline_coupler(1)		      create_bmp_for_symmetri-
       cal_stripline(1)	   design_coupler(1)   find_optimal_dimensions_for_mi-
       crostrip_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

Dr. David Kirkby	   atlc-4.4.2 10th Sept	2003		       atlc(1)


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