!
! This file is part of SACAMOS, State of the Art CAble MOdels for 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) 2016-2018 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_set_parameters
! SUBROUTINE shielded_twisted_pair_set_internal_domain_information
! SUBROUTINE shielded_twisted_pair_plot!
! NAME
!     shielded_twisted_pair_set_parameters
!
! AUTHORS
!     Chris Smartt
!
! DESCRIPTION
!     Set the overall parameters for a shielded_twisted_pair cable
!
! COMMENTS
!      
!
! HISTORY
!
!     started 5/9/2016 CJS based on shielded_twisted_pair.F90
!     16/11/2017 CJS Include network synthesis process to replace s-domain transfer functions
!
!
SUBROUTINE shielded_twisted_pair_set_parameters(cable)

USE type_specifications

IMPLICIT NONE

! variables passed to subroutine

  type(cable_specification_type),intent(INOUT)    :: cable

! local variables

! START

  cable%cable_type=cable_geometry_type_shielded_twisted_pair
  cable%tot_n_conductors=3
  cable%tot_n_domains=3
  cable%n_external_conductors=1
  cable%n_internal_conductors=2
  cable%n_internal_domains=2     ! note we have both a common mode and a differential mode internal domain
  cable%n_parameters=8
  cable%n_dielectric_filters=2
  cable%n_transfer_impedance_models=1

END SUBROUTINE shielded_twisted_pair_set_parameters
!
! NAME
!     shielded_twisted_pair_set_internal_domain_information
!
! AUTHORS
!     Chris Smartt
!
! DESCRIPTION
!     Set the overall parameters for a shielded_twisted_pair cable
!
! COMMENTS
!     Set the dimension of the domain transformation matrices to include an external reference conductor for the cable 
!      
!
! HISTORY
!
!     started 5/9/2016 CJS based on shielded_twisted_pair.F90
!     8/9/2016 CJS common mode/ differential mode loss correction
!     19/9/2016 CJS frequency dependent dielectric in Laplace solver
!     2/11/2016 CJS inhomogeneous dielectric in twisted pair model
!     15/12/2016 CJS frequeny dependent dielectric in twisted pair model with Laplace solver
!     8/5/2017         CJS: Include references to Theory_Manual
!
!
SUBROUTINE shielded_twisted_pair_set_internal_domain_information(cable)

USE type_specifications
USE constants
USE general_module
USE maths
USE PUL_parameter_module

IMPLICIT NONE

! variables passed to subroutine

  type(cable_specification_type),intent(INOUT)    :: cable

! local variables

  integer :: n_conductors
  integer :: dim

  integer :: domain

  type(PUL_type)    :: PUL
  
  real(dp) :: L11,L12
  real(dp) :: C11,C12
  
  real(dp) :: LC,LD,CC,CD
  logical  :: dielectric_is_homogeneous
  
  real(dp) :: C_air
  type(Sfilter) :: jw
  
  integer :: i
  
  real(dp) :: epsr
 
! variables for cable parameter checks 
  logical :: cable_spec_error
  real(dp) :: rw
  real(dp) :: s
  real(dp) :: rd
  real(dp) :: rs
  real(dp) :: rd2
  real(dp) :: t
  real(dp) :: sigma_w
  real(dp) :: sigma_s
 
  type(Sfilter) :: epsr1,epsr2,ZT
  type(Sfilter) :: YC,YD
  
  character(LEN=error_message_length) :: message 

! START

! Check the cable parameters

  rw=cable%parameters(1)
  rd=cable%parameters(2)
  s=cable%parameters(3)
  rs=cable%parameters(4)
  t=cable%parameters(5)
  rd2=cable%parameters(6)
  sigma_w=cable%parameters(7)
  sigma_s=cable%parameters(8)
  
  epsr1=cable%dielectric_filter(1)
  epsr2=cable%dielectric_filter(2)
  ZT=cable%transfer_impedance(1)
  
  cable_spec_error=.FALSE.    ! assume no errors initially
  message=''
  CALL shielded_twisted_pair_check(rw,rd,s,rs,rd2,cable_spec_error,cable%cable_name,message)
  CALL conductivity_check(sigma_w,cable_spec_error,cable%cable_name,message)
  CALL conductivity_check(sigma_s,cable_spec_error,cable%cable_name,message)
  CALL dielectric_check(epsr1,cable_spec_error,cable%cable_name,message)
  CALL dielectric_check(epsr2,cable_spec_error,cable%cable_name,message)
  CALL transfer_impedance_check(Zt,cable_spec_error,cable%cable_name,message)
  CALL surface_impedance_check(ZT,sigma_s,rs,t,cable_spec_error,cable%cable_name,message)
  
  if (cable_spec_error) then       
    run_status='ERROR in cable_model_builder, error on parameters for cable:'//trim(cable%cable_name)//'. '//trim(message)
    CALL write_program_status()
    STOP 1
  end if

! pre-calculate inductance matrix elements for two conductors in a cylindrical shield

  domain=1

  epsr=evaluate_Sfilter_high_frequency_limit(epsr1)
  
! First calculate the elements of the 2x2 inductance matrix before 
! determining the common mode and differential mode inductance and capacitance

  jw=jwA_filter(1d0)

  if (use_laplace) then
  
! allocate memory for the PUL parameter solver interface

    if(verbose) write(*,*)'Domain:',domain
    if(verbose) write(*,*)'Allocating PUL data structure for shielded twisted pairs'
    n_conductors=3
    
    CALL allocate_and_reset_PUL_data(PUL,n_conductors)
    
    PUL%shape(1:n_conductors)=circle
   
    PUL%x(1)=-s/2d0
    PUL%y(1)=0.0
    PUL%r(1)=rw
    PUL%rd(1)=rd
    PUL%epsr(1)=epsr1
    
    PUL%x(2)=s/2d0
    PUL%y(2)=0.0
    PUL%r(2)=rw
    PUL%rd(2)=rd
    PUL%epsr(2)=epsr1
    
    PUL%epsr_background = 1d0  ! permittivity of homogeneous dielectric medium surrounding conductors (air)
  
! no ground plane
    PUL%ground_plane_present=.FALSE.
      
! add overshield i.e. the twinax shield
    PUL%overshield_present=.TRUE.
    PUL%overshield_x = 0d0          ! shield is centred at the origin in this calculation
    PUL%overshield_y = 0d0
    PUL%overshield_r = rs           ! shielded twisted pair shield radius
    
    CALL PUL_LC_Laplace(PUL,cable%cable_name,cable%Y_fit_model_order,cable%Y_fit_freq_spec,domain) 

! Theory_Manual_Eqn 3.21
! there may be slight asymmmetry due to meshing so average diagonal and off diagonal elements    
    L11=(PUL%L%mat(1,1)+PUL%L%mat(1,1))/2d0
    L12=(PUL%L%mat(1,2)+PUL%L%mat(2,1))/2d0
    
    C11=(PUL%C%mat(1,1)+PUL%C%mat(1,1))/2d0
    C12=(PUL%C%mat(1,2)+PUL%C%mat(2,1))/2d0
    
    dielectric_is_homogeneous=.FALSE.
    
    CALL shielded_twisted_pair_cm_dm_parameter_calculation(L11,L12,C11,C12,epsr,LC,LD,CC,CD,dielectric_is_homogeneous)    

! Theory_Manual_Eqn 3.22
    YD=0.5d0*( PUL%Yfilter%sfilter_mat(1,1)+((-1d0)*PUL%Yfilter%sfilter_mat(1,2)) )
    YC=2.0d0*( PUL%Yfilter%sfilter_mat(1,1)+PUL%Yfilter%sfilter_mat(1,2) )           
    
  else

! See C.R. Paul, 1st edition, equation 3.67a,b with cos(thetaij)=-1! Theory_Manual_Eqn 2.27, 2.28
    L11=(mu0/(2d0*pi))*log( (rs**2-(s/2d0)**2)/(rs*rw) )
    L12=(mu0/(2d0*pi))*log( (s/(2d0*rs)) * (rs**2+(s/2d0)**2)/(2d0*(s/2d0)**2) )
    
    dielectric_is_homogeneous=.TRUE.
    
    CALL shielded_twisted_pair_cm_dm_parameter_calculation(L11,L12,C11,C12,epsr,LC,LD,CC,CD,dielectric_is_homogeneous)    

    YD=CD*jw
    YC=CC*jw
    
  end if  
    
! DOMAIN 1: Set the parameters for the internal differential mode domain  
  domain=1
    
  cable%n_internal_conductors_in_domain(domain)=2
    
! The number of modes in the internal differential mode domain is 1

  dim=1
  
  cable%L_domain(domain)%dim=dim
  ALLOCATE(cable%L_domain(domain)%mat(dim,dim))
  cable%C_domain(domain)%dim=dim
  ALLOCATE(cable%C_domain(domain)%mat(dim,dim))
  
  cable%Z_domain(domain)%dim=dim
  ALLOCATE(cable%Z_domain(domain)%sfilter_mat(dim,dim))
  cable%Y_domain(domain)%dim=dim
  ALLOCATE(cable%Y_domain(domain)%sfilter_mat(dim,dim))
  
  cable%L_domain(domain)%mat(1,1)=LD 
  cable%Z_domain(domain)%sfilter_mat(1,1)=cable%L_domain(domain)%mat(1,1)*jw
  
  cable%C_domain(domain)%mat(1,1)=CD
  cable%Y_domain(domain)%sfilter_mat(1,1)=YD
  
! DOMAIN 2: Set the parameters for the internal common mode domain  
  domain=2
    
  cable%n_internal_conductors_in_domain(domain)=2
    
! The number of modes in the internal differential mode domain is 1

  dim=1
  cable%L_domain(domain)%dim=dim
  ALLOCATE(cable%L_domain(domain)%mat(dim,dim))
  cable%C_domain(domain)%dim=dim
  ALLOCATE(cable%C_domain(domain)%mat(dim,dim))
  
  cable%Z_domain(domain)%dim=dim
  ALLOCATE(cable%Z_domain(domain)%sfilter_mat(dim,dim))
  cable%Y_domain(domain)%dim=dim
  ALLOCATE(cable%Y_domain(domain)%sfilter_mat(dim,dim))

  cable%L_domain(domain)%mat(1,1)=LC 
  cable%Z_domain(domain)%sfilter_mat(1,1)=cable%L_domain(domain)%mat(1,1)*jw
  
  cable%C_domain(domain)%mat(1,1)=CC
  cable%Y_domain(domain)%sfilter_mat(1,1)=YC
 
  if (use_laplace) CALL deallocate_PUL_data(PUL)  ! deallocate the PUL data structure
   
! Set the domain decomposition matrices ! Theory_Manual_Eqn 6.11, 6.12

! The dimension of the domain transformation matrices is 4

  dim=4
  cable%MI%dim=dim
  ALLOCATE(cable%MI%mat(dim,dim))
  cable%MV%dim=dim
  ALLOCATE(cable%MV%mat(dim,dim))

  cable%MI%mat(1,1)=0.5D0
  cable%MI%mat(1,2)=-0.5d0
  cable%MI%mat(1,3)=0d0
  cable%MI%mat(1,4)=0d0
  
  cable%MI%mat(2,1)=1d0
  cable%MI%mat(2,2)=1d0
  cable%MI%mat(2,3)=0d0
  cable%MI%mat(2,4)=0d0
  
  cable%MI%mat(3,1)=1d0
  cable%MI%mat(3,2)=1d0
  cable%MI%mat(3,3)=1d0
  cable%MI%mat(3,4)=0d0
  
  cable%MI%mat(4,1)=1d0
  cable%MI%mat(4,2)=1d0
  cable%MI%mat(4,3)=1d0
  cable%MI%mat(4,4)=1d0


  cable%MV%mat(1,1)=1D0
  cable%MV%mat(1,2)=-1d0
  cable%MV%mat(1,3)=0d0
  cable%MV%mat(1,4)=0d0
  
  cable%MV%mat(2,1)=0.5d0
  cable%MV%mat(2,2)=0.5d0
  cable%MV%mat(2,3)=-1d0
  cable%MV%mat(2,4)=0d0
  
  cable%MV%mat(3,1)=0d0
  cable%MV%mat(3,2)=0d0
  cable%MV%mat(3,3)=1d0
  cable%MV%mat(3,4)=-1d0
  
  cable%MV%mat(4,1)=0d0
  cable%MV%mat(4,2)=0d0
  cable%MV%mat(4,3)=0d0
  cable%MV%mat(4,4)=1d0

! Set the local reference conductor numbering  
  ALLOCATE( cable%local_reference_conductor(3) )
  cable%local_reference_conductor(1)=2              ! differential mode, reference is the second conductor
  cable%local_reference_conductor(2)=3              ! common mode, reference is the shield conductor
  cable%local_reference_conductor(3)=0              ! external domain conductor, reference not known

! Set the local domain information: include a reference conductor in the count
  ALLOCATE( cable%local_domain_n_conductors(1:cable%tot_n_domains) )
  cable%local_domain_n_conductors(1)=2              ! differential mode domain 
  cable%local_domain_n_conductors(2)=2              ! common mode
  cable%local_domain_n_conductors(3)=2              ! external domain 
  
! Set the external domain conductor and dielectric information
   
  ALLOCATE( cable%external_model(cable%n_external_conductors) )
  CALL reset_external_conductor_model(cable%external_model(1))
  cable%external_model(1)%conductor_type=circle
  cable%external_model(1)%conductor_radius=rs 
  cable%external_model(1)%dielectric_radius=rd2
  cable%external_model(1)%dielectric_epsr=epsr2 
    
! set the conductor impedance model for the differential mode
  cable%conductor_impedance(1)%impedance_model_type=impedance_model_type_cylindrical_with_conductivity
  cable%conductor_impedance(1)%radius=rw
  cable%conductor_impedance(1)%conductivity=sigma_w
  cable%conductor_impedance(1)%Resistance_multiplication_factor=1.5d0

! set the conductor impedance model for the common mode
  cable%conductor_impedance(2)%impedance_model_type=impedance_model_type_cylindrical_with_conductivity
  cable%conductor_impedance(2)%radius=rw
  cable%conductor_impedance(2)%conductivity=sigma_w
  cable%conductor_impedance(2)%Resistance_multiplication_factor=0.5d0
      
! set the impedance model for the shield conductor
    
  cable%conductor_impedance(3)%impedance_model_type=impedance_model_type_cylindrical_shield
  cable%conductor_impedance(3)%radius=rs
  cable%conductor_impedance(3)%thickness=t
  cable%conductor_impedance(3)%conductivity=sigma_s
  cable%conductor_impedance(3)%ZT_filter=ZT
  
! Deallocate all filters   
  CALL deallocate_Sfilter(epsr1)
  CALL deallocate_Sfilter(epsr2)
  CALL deallocate_Sfilter(ZT)
  CALL deallocate_Sfilter(jw)
  
  ALLOCATE( cable%conductor_label(1:cable%tot_n_conductors) )
  cable%conductor_label(1)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 1 : Twisted pair wire 1'
  cable%conductor_label(2)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 2 : Twisted pair wire 2'
  cable%conductor_label(3)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 3 : Shield'

END SUBROUTINE shielded_twisted_pair_set_internal_domain_information
!
! NAME
!     shielded_twisted_pair_plot
!
! AUTHORS
!     Chris Smartt
!
! DESCRIPTION
!     plot shielded twisted pair cable 
!
! COMMENTS
!     the angle has NO impact here due to the twisting
!
! HISTORY
!
!     started 5/9/2016 CJS based on shielded_twisted_pair.F90
!
!
SUBROUTINE shielded_twisted_pair_plot(cable,x_offset,y_offset,theta,xmin,xmax,ymin,ymax)

USE type_specifications
USE general_module

IMPLICIT NONE

! variables passed to subroutine

  type(cable_specification_type),intent(IN)    :: cable
  
  real(dp),intent(IN) :: x_offset,y_offset,theta
  real(dp),intent(INOUT) ::  xmin,xmax,ymin,ymax

! local variables

  real(dp) :: x,y,r,rd
  real(dp) :: s

! START

! Inner conductors
  r=cable%parameters(1)   ! inner conductor radius
  rd=cable%parameters(2)  ! inner dielecric radius
  s=cable%parameters(3)   ! inner conductor separation

! plot inner conductor, 1
  x=x_offset+(s/2d0)
  y=y_offset

  CALL write_circle(x,y,r,conductor_geometry_file_unit,xmin,xmax,ymin,ymax)

! plot inner conductor, 2
  x=x_offset-(s/2d0)
  y=y_offset

  CALL write_circle(x,y,r,conductor_geometry_file_unit,xmin,xmax,ymin,ymax)

! plot inner dielectric, 1
  x=x_offset+(s/2d0)
  y=y_offset

  CALL write_circle(x,y,rd,dielectric_geometry_file_unit,xmin,xmax,ymin,ymax)

! plot inner dielectric, 2
  x=x_offset-(s/2d0)
  y=y_offset

  CALL write_circle(x,y,rd,dielectric_geometry_file_unit,xmin,xmax,ymin,ymax)

! plot shield conductor
  r=cable%parameters(4)   ! outer shield radius
  x=x_offset
  y=y_offset

  CALL write_circle(x,y,r,conductor_geometry_file_unit,xmin,xmax,ymin,ymax)

! plot circular dielectric
  rd=cable%parameters(6)   ! outer dielectric radius
  x=x_offset
  y=y_offset

  CALL write_circle(x,y,rd,dielectric_geometry_file_unit,xmin,xmax,ymin,ymax)
  
  RETURN
  
END SUBROUTINE shielded_twisted_pair_plot