!  Calculate normal incidence RF transmission through a free-standing
!  thin conductive mesh with uniform wire spacing in x and y directions.

!  Reference:  Kohin, Wein, Traylor, Chase, and Chapman,
!  "Analysis and Design of Transparent Conductive Coatings and Filters",
!  Optical Engineering, May 1993, pp. 911-925.

!  Program inputs are:
!    Mesh wire width in microns
!    Mesh wire spacing in microns

!  Program outputs are:
!    Program input values
!    Normal incidence mesh transmission in dB as a function of frequency in GHz

!  For my purposes I find it easier to just directly key the input values, 
!  min/max frequency, and frequency increments into the macro rather than use
!  input boxes.  Feel free to modify this macro as you see fit.  Be sure to 
!  keep all units consistent.

!  Author:  Mike I. Jones  6/13/96  updated 9/04/99

OUTPUT SCREEN


!  PROGRAM INPUTS:


WIRE_WIDTH_IN_MICRONS = 20

WIRE_SPACING_IN_MICRONS = 250

MIN_FREQ_IN_GHZ = 1
MAX_FREQ_IN_GHZ = 20
FREQ_INCREMENT_IN_GHZ = 1


!  BEGIN CALCULATIONS:


PI = 3.141592653589793

! VELOCITY OF LIGHT IN A VACUUM IN CM/SEC.

VC_CM = 2.99792458E10

WIRE_WIDTH_IN_CM = WIRE_WIDTH_IN_MICRONS / 10000

WIRE_SPACING_IN_CM = WIRE_SPACING_IN_MICRONS / 10000

FORMAT 6.1
PRINT
PRINT "  Normal Incidence RF Transmission Through a Free-"
PRINT "Standing Conductive Mesh with Uniformly Spaced Wires"
PRINT
PRINT "Mesh wire width in microns = ",WIRE_WIDTH_IN_MICRONS
PRINT
PRINT "Mesh wire spacing in microns = ",WIRE_SPACING_IN_MICRONS
PRINT
PRINT "Frequency (GHz)    Mesh Transmission (dB)"

FOR FREQUENCY_IN_GHZ = MIN_FREQ_IN_GHZ , MAX_FREQ_IN_GHZ , FREQ_INCREMENT_IN_GHZ
  FREQUENCY_IN_HZ = FREQUENCY_IN_GHZ * 1E9
  WAVELENGTH_IN_CM = VC_CM / (FREQUENCY_IN_HZ)
  TRANS = ( 2 * WIRE_SPACING_IN_CM / WAVELENGTH_IN_CM )
  TRANS = TRANS * LOGE( SINE( PI * WIRE_WIDTH_IN_MICRONS / (2*WIRE_SPACING_IN_MICRONS) )  )
  TRANS = TRANS * TRANS
  TRANS_dB = -10 * LOGT(TRANS)
  FORMAT 8.1
  PRINT FREQUENCY_IN_GHZ,
  FORMAT 24.2
  PRINT TRANS_dB
NEXT FREQUENCY_IN_GHZ

END