##########################################################
# cross_talk_z0.lsf
#
# Calculates the characteristic impedance/neff of the isolated
# microstrip line, the coupled microstrip line's even 
# and odd mode, and the coaxial waveguide using the built 
# in characteristic impedance calculator. The dimensions 
# correspond to the cross_talk.fsp simulation file.
# 
# The script creates a port to extract the effective parameters:
# neff/Z0 and deletes the port at the end.
#
# Copyright 2016 Lumerical Solutions Inc
##########################################################
clear;

#Dimensions
w=4.8e-3;g=4.8e-3;subh=1.55e-3;b=2.9e-3;a=0.8e-3;
#create port
name="z0_port";
addport;set("name", name);set("injection axis", "z");
#set port size for one microstrip
set("x",-g/2-w/2);set("y min",-subh);set("y max",20e-3);set("x span",w+1.9*g);
set("calculate characteristic impedance",1);set ("x1",-g/2-w-g*0.95);set("x2",-w/2+0.95*g);set("y1",-subh);set("y2",20e-3);
updateportmodes;  #one microstrip
neff=getresult("::model::FDTD::ports::"+name,"neff");n_ms=real(neff.neff);
set("mode selection", "user select");

#set port size for coupled microstrip
set("x min",-25e-3);set("x max",25e-3);set("x1",-25e-3);set("x2",25e-3);

updateportmodes(1); #even mode
neff=getresult("::model::FDTD::ports::"+name,"neff");n_ev=real(neff.neff);
Z0=getresult("::model::FDTD::ports::"+name,"impedance");Z0_ev=real(Z0.impedance*2);
set("x2",-w/2+0.95*g);

updateportmodes(2);#odd mode
neff=getresult("::model::FDTD::ports::"+name,"neff");n_odd=real(neff.neff);
Z0=getresult("::model::FDTD::ports::"+name,"impedance");Z0_odd=real(Z0.impedance/2);
delete; #remove port
select("::model::FDTD::ports::port 1");set("x1",-w/2-g/2-b/2);set("x2",-w/2-g/2+b/2);set("y1",-b/2+a);set("y2",b/2+a);
updateportmodes; #coax
Z0=getresult("::model::FDTD::ports::port 1","impedance");Z0_coax=real(Z0.impedance);