shielded_twisted_pair_cm_dm_parameter_calculation.F90
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!
! This file is part of SACAMOS, State of the Art CAble MOdels in Spice.
! It was developed by the University of Nottingham and the Netherlands Aerospace
! Centre (NLR) for ESA under contract number 4000112765/14/NL/HK.
!
! Copyright (C) 2016-2017 University of Nottingham
!
! SACAMOS is free software: you can redistribute it and/or modify it under the
! terms of the GNU General Public License as published by the Free Software
! Foundation, either version 3 of the License, or (at your option) any later
! version.
!
! SACAMOS is distributed in the hope that it will be useful, but
! WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
! or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
! for more details.
!
! A copy of the GNU General Public License version 3 can be found in the
! file GNU_GPL_v3 in the root or at <http://www.gnu.org/licenses/>.
!
! SACAMOS uses the EISPACK library (in /SRC/EISPACK). EISPACK is subject to
! the GNU Lesser General Public License. A copy of the GNU Lesser General Public
! License version can be found in the file GNU_LGPL in the root of EISPACK
! (/SRC/EISPACK ) or at <http://www.gnu.org/licenses/>.
!
! The University of Nottingham can be contacted at: ggiemr@nottingham.ac.uk
!
! File Contents:
! SUBROUTINE shielded_twisted_pair_cm_dm_parameter_calculation
!
! NAME
! shielded_twisted_pair_cm_dm_parameter_calculation
!
! AUTHORS
! Chris Smartt
!
! DESCRIPTION
! from the L and C matrix elements of a shielded twisted pair, calculate the
! L and C matrix elements for the common mode- differential model model
! If the dielectric in the shield is homogeneous then the capacitance
! terms are calculated from the inductance values and the relative permittivity of the dielectric.
!
! COMMENTS
!
!
! HISTORY
!
! started 2/11/2016 CJS
!
!
SUBROUTINE shielded_twisted_pair_cm_dm_parameter_calculation(L11,L12,C11,C12,epsr,LC,LD,CC,CD,dielectric_is_homogeneous)
USE type_specifications
USE constants
IMPLICIT NONE
! variables passed to subroutine
! diagonal and off diagonal elements of inductance matrix for a shielded twisted pair
real(dp),INTENT(IN) :: L11,L12
! diagonal and off diagonal elements of capacitance matrix for a shielded twisted pair - only used for homogeneous
! dielectric case when capacitance matrix can be calculated from the inverse of the inductance matrix
real(dp),INTENT(IN) :: C11,C12
real(dp),INTENT(IN) :: epsr ! relative permittivity for homogeneous dielectric case
logical,INTENT(IN) :: dielectric_is_homogeneous ! flag to indicate the homogeneous dielectric case
real(dp),INTENT(OUT) :: LC,LD ! common mode and differential mode inductance
real(dp),INTENT(OUT) :: CC,CD ! common mode and differential mode capacitance
! local variables
! START
LD=2d0*(L11-L12) ! Theory_Manual_Eqn 3.21
LC=0.5d0*(L11+L12) ! Theory_Manual_Eqn 3.21
if (dielectric_is_homogeneous) then
CD=eps0*mu0*epsr/LD
CC=eps0*mu0*epsr/LC
else
CD=0.5d0*(C11-C12) ! Theory_Manual_Eqn 3.22
CC=2d0*(C11+C12) ! Theory_Manual_Eqn 3.22
end if
END SUBROUTINE shielded_twisted_pair_cm_dm_parameter_calculation