lookupreadnportsparameter - Script command – Ansys Optics

INTERCONNECT

Returns an interpolated s-parameter cell for specific design parameters from an xml file containing a lookup table of design.

The xml file should have a lookup table associating s-parameter data files with design parameters. Each s-parameter file associated by the table should be compatible with the Optical N Port S-Parameter element, in the exact same format, and should not contain any header.

Syntax

Description

out = lookupreadnportsparameter ("filename","table",design,"extracted");

Returns an interpolated s-parameter cell from an xml file containing a lookup table of design:

filename: Name of the xml file.
table: Name of the lookup table located inside the xml file.
design: Cell containing multiple structures defining the target design to extract.
extracted: Name of the parameter inside the lookup table that holds names of the s-parameter data file for each design.

out = lookupreadnportsparameter ("filename","table",design,"extracted", opt);

Returns an interpolated s-parameter cell from an xml file containing a lookup table of design with interpolation options in the structure opt:

filename: Name of the xml file.
table: Name of the lookup table located inside the xml file.
design: Cell containing multiple structures defining the target design to extract.
extracted: Name of the parameter inside the lookup table that holds names of the s-parameter data file for each design.
opt: Structure setting interpolation options. The structure fields are described in the table below.

The option structure has the following fields, the spelling of each field is case-sensitive.

Field

Description

method

The method used for interpolation. The following options are supported:

spline: Spline interpolation method, this is the default method.
Geodesic: Geodesic interpolation method which ensures smooth transitions. When geodesic interpolation is selected, a similarity check is performed on original data points near the interpolated point used for the interpolation, if these points are not sufficiently similar, the data is coarse, and a warning is displayed. This method cannot be used for extrapolation.

passivity

Whether passivity is enforced for the s-parameter data prior to interpolation. This field only affects results when “geodesic” is selected as the interpolation method. When data is non-passive, a warning message is always displayed for geodesic interpolation.

The following options are supported:

enforce: Ensures S-matrix is passive by making sure that the induced 2-norm of the s-parameters is less than 1. This is the default method.
ignore: Ignores passivity of the s-parameters and interpolates as-is.

Note: For more information on how passivity is enforced, see this Knowledge Base article.

Example

Loads the s-parameters of a coupler depending on user defined design parameters set up target for interpolation:

filename = "coupler.ixml";
table = "coupler";
radius = 3e-06;
gap = 3e-07;
design = cell(2);
#design (input parameters)
design{1} = struct;
design{1}.name = "radius";
design{1}.value = radius;
design{2} = struct;
design{2}.name = "gap";
design{2}.value = gap;

Interpolate parameters and load into S-parameter cell array using spline interpolation

?M = lookupreadnportsparameter( filename, table, design, "out_filename" );

Interpolate parameters and load into S-parameter cell array using geodesic interpolation, ignoring passivity of the element

?M = lookupreadnportsparameter( filename, table, design, "out_filename", {"method":"geodesic","passivity":"ignore" );

Set parameters to element

addelement("Optical N Port S-Parameter");
setvalue('SPAR_1','s parameters',M);

“coupler.ixml” is a lookup table containing a map between coupler parameters and different s-parameters:

<?xml version="1.0" encoding="UTF-8"?>
<lumerical_lookup_table version="1.0" name = "coupler">
  <association>
    <design>
      <value name="radius" type="double">3e-06</value>
      <value name="gap" type="double">3e-07</value>
    </design>
    <extracted>
      <value name="out_filename" type="string">radius_3_gap_3.txt</value>
    </extracted>
  </association>
</lumerical_lookup_table>

For example “radius_3_gap_3.txt” file contains s-parameters for the ‘Optical N Port S-Parameter’ element

("port 1","TE",1,"port 1",1,"transmission")
(3,3)
 2.262580000000e+014 1.034036580296e-002 -2.629253819969e+000
 2.275690000000e+014 9.716591457652e-003 -2.734774978072e+000
 2.288790000000e+014 6.884340821788e-003 -2.838683842048e+000
("port 1","TE",1,"port 2",1,"transmission")
(3,3)
 2.262580000000e+014 9.847090174703e-001 1.376105202083e-001
 2.275690000000e+014 9.959778891317e-001 1.450376288706e-001
 2.288790000000e+014 1.002869828593e+000 1.483183421805e-001

lookupreadnportsparameter - Script command

Associated files

Related articles