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create_bmp_for_circ_in_circ(General Commands Mancreate_bmp_for_circ_in_circ(1)

       create_bmp_for_circ_in_circ  -  bitmap generator	for circular conductor
       inside circular conductor (part of atlc)

       create_bmp_for_circ_in_circ [options... ] D d O Er filename.bmp

       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_circ_in_circ is a	pre-processor  for  atlc,  the	finite
       difference  program  that  is used to calculate the properties of a two
       and three conductor electrical transmission  line  of  arbitrary	 cross
       section.	 The program create_bmp_for_circ_in_circ is used as a fast way
       of generating bitmaps (there is no need to use a	graphics program), for
       a  circular conductor inside a circular conductor (coaxial conductors),
       like this:

		       ****		    ****
		    ****    <-----d------>     ****
		  ***		 *****		  ***
		***	      ***********	    ***
	      ***	     *************	      ***
	     ***	    ***************	       ***
	    ***	     ^	    ***************		***
	   ***	     |	    ***************		 ***
	  ***	     |	     *************		  ***
	  **	     O	      ***********		   **
	 ***	     |		  ***			   ***
	 **	     |					    **
	 **						    **
	 **						    **
	 **						    **
	 ***						   ***
	  **						   **
	  ***						  ***
	   **						  **
	    **						 **
	     **						**
	      ***				      ***
	       ****				    ****
		 ****				  ****
		   *****		       *****
		      ******		   ******

       The parameter 'D' is the	inner dimensions of the	 outer	conductor  and
       'd'  is the outer diameter of the inner conductor.  The inner conductor
       is offset 'h' from the centre of	the outer conductor. The whole	region
       is surrounded by	a dielectric of	relative permittivity 'Er'.

       The  bitmap  is	printed	to 'outfile.bmp' - the last command line argu-

       The bitmaps produced  by	 create_bmp_for_circ_in_circ  are  24-bit  bit
       colour bitmaps, as are required by atlc.

       The permittivities of the dielectric 'Er' determines the	colours	in the
       bitmap. If Er is	1.0, 1.006, 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 Er is not one
       of  those  permittivities, the region of	permittivity Er	will be	set to
       the colour 0xCAFF00. The	program	atlc does not know what	 this  permit-
       tivity is, so atlc, must	be told	with the command line option -d, as in
       example 4 below.

       -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.

       -f outfile
       Set the output filename.	By default, the	bitmap is sent to stdout,  but
       it *must* be sent to a file, with this option, or as described above.

       Causes  create_bmp_for_circ_in_circ to print some data to stderr. Note,
       nothing extra goes to standard output, as that is expected to be	 redi-
       rected 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  re-
       conised	by atlc, or you	must define it with a command line option (see
       OPTIONS and example 5 below).
       The following conductors	are reconised by atlc:
       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 0x000000	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 reconised	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)
       blue	 000,000,255 or	0x0000FF 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	ox696969 as Er=6.15  (duroid 6006)
       L. gray	 240,240,240 or	0xDCDCDC as Er=10.2  (duroid 6010)

       Although	create_bmp_for_circ_in_circ is used  for  circular  inner  and
       outer  conductors,  the	outside	 of  the outer conductor is drawn as a
       square. This is for convenience and makes no difference to the calcula-
       tions. The inside is of the outer conductor is drawn as a circle.

       Here  are  a  few  examples  of the use of create_bmp_for_circ_in_circ.
       Again, see  the	html  documentation  in	 atlc-X.Y.Z/docs/html-docs/in-
       dex.html	for more examples.

       1)  In the first	example, the outer conductor has an inside diameter of
       12 units	(inches, mm, feet etc.), the inner has an outside diameter  of
       3.9  units.   The inner is placed centrally (h=0) and the dielectric is
       vacuum (Er=1.0).
       % create_bmp_for_circ_in_circ 12	3.9 0 1.0 coaxial_1.bmp
       % atlc coaxial_1.bmp
       atlc will indicate the correct value of impedance to be	67.3667	 Ohms,
       whereas	an exact analysis will show the	true value to be 67.4358 Ohms,
       so atlc has an error of 0.102%.

       2) In this second example, the conductor	sizes are the sames as in  ex-
       ample  1, but the inner is located 3.5 units off-centre and the dielec-
       tric has	a relative permittivity	of 2.1 (Er of PTFE) The	output is sent
       to a file not_in_centre.bmp which is then processed by atlc
       % create_bmp_for_circ_in_circ 12	3.9 3.5	2.1 not_in_centre.bmp
       % atlc not_in_centre.bmp
       The  impedance  of  this	 is  theoretically  24.315342  Ohms,  as  cre-
       ate_bmp_for_circ_in_circ	will calculate for  you.  atlc's  estimate  is
       24.2493 Ohms, an	error of only -0.271 %.

       3)  In  the  third example the bitmap is	made larger, to	increase accu-
       racy, but otherwise this	is identical to	the previous one.
       % create_bmp_for_circ_in_circ -b8 12  3.9  3.5  2.1  bigger_not_in_cen-
       % atlc bigger_not_in_centre.bmp
       This  time atlc will take much longer to	calculate Zo, since the	bitmap
       is larger and so	it needs to do more calculations. However,  the	 final
       result  should  be  more	accurate. In this case,	the result reported is
       24.2461 Ohms, an	error that's marginally	smaller	than before  at	 0.285
       %.   It	is  possible there may be something to be gained by decreasing
       the cutoff at larger grids, so this is being investigated. However, er-
       rors almost always below	0.25 %,	no matter what is being	analysed.

       In  the	fourth example,	a material with	a relativity permittivity 7.89
       of   is	 used.	 There	 is   no   change   in	 how   to   use	  cre-
       ate_bmp_for_circ_in_circ, but since this	permittivity is	not one	of the
       pre-defined values (see COLOURS), we must tell atlc what	 it  is.   The
       colour will be set an olive green one, with a hexacidcal	representation
       of red=0xCA, blue=OxFF and green	= 0x00.	This just happens  to  be  the
       default	colour	used when the permittivity is unknown. So atlc must be
       given this information, like thisL
       % create_bmp_for_circ_in_circ 23	9 0 7.89 an_odd_er.bmp
       % atlc -d CAFF00=7.89 an_odd_er.bmp This	has a theoretical impedance of
       20.041970 Ohms, but atlc	version	3.0.1 will calculate it	to be 20.0300,
       an error	of -0.058 % !!!	If you look at the file	an_odd_er.bmp  with  a
       graphics	 package, you will see there are 3 colours in it - the red in-
       ner conductor, the green	outer and an olive-green dielectric.

       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 10th Sept	create_bmp_for_circ_in_circ(1)


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