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       create_bmp_for_microstrip_coupler  -  bitmap  generator	for microstrip
       coupler (part of	atlc)

       create_bmp_for_microstrip_coupler [-b bmp_size] [-v] w s	g h t Er1  Er2

       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.

       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_mi-
       crostrip_coupler	is used	as a fast way of generating bitmaps (there  is
       no  need	 to use	a graphics program), for microstrip couplers. Hence if
       the dimensions of a coupler are known the odd mode, even	mode,  differ-
       ential  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 re-
       peated calls to	create_bmp_for_microstrip_coupler. The	structure  for
       which  bitmaps  are  generated  by create_bmp_for_microstrip_coupler is
       shown below.

       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	|

       The parameters 'W' and 'H' and the inner	dimensions of the a metal  en-
       closure.	 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  di-
       electic 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.

       -C  Causes create_bmp_for_microstrip_coupler to print copyright and li-
       censing 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 de-
       fault 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.

       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.

       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 lev-
       els 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

       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

       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 pur-

       Here are	a few examples of the  use  of	create_bmp_for_microstrip_cou-
       pler.  Again,  see  the	html  documentation  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 surrounded by
       an outer	with internal dimensions of 61.5 x 20.1	mm. There is  a	 mate-
       rial  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 oth-
       erwise  this  is	identical to the second	example.  % create_bmp_for_mi-
       crostrip_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_mi-
       crostrip_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.

       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_cou-
       pler(1)	create_bmp_for_rect_in_circ(1)	 create_bmp_for_stripline_cou-
       pler(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

Dr. David Kirkby	   atlc-4.4.2 10thcreate_bmp_for_microstrip_coupler(1)


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