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spar_fixed parameter script file

Port Definitions

Variable Type Description
ports Cell

A cell array containing structs which have information about each port. Every struct must contain the following fields:

  • name: The name of the port, which will be visible to the end user. This name should be consistent with the name that will be used for netlisting.
  • dir: The directionality of the port, either "Input", "Output", or "Bidirectional"
  • type: The signal type of the port, which should be "Optical Signal" for waveguides
  • pos: The side of the model which the port will be displayed on, either "Left", "Right", "Top", or "Bottom"
  • loc: The placement of the port on the side defined by loc, provided as a coordinate between 0 and 1.

Photonic Model 

Variable Type Description

photonic_model 

string 

String containing the name of the photonic model used for this template. 

Please visit here for a list of all available photonic models.  

Cosmetic Variables

Variable Type Description
description String A string containing a brief description of the model, which will be displayed to the end user.
prefix String A string containing the prefix of the model, which will be used within interconnect to provide incrementing element names for each successive element that is added to the simulation layout.
notes Cell

A cell array which provides model notes that will be displayed to the end user. Each element of the cell is a struct with the fields:

  • property: The name of the note.
  • value: The contents of the note.

Modeling Variables

Variable Type Description
spar_filename String A string containing the filename of the s-parameter data file for this element. This must include the extension of the file (.txt)
digital_filter_type String

A string containing the type of digital filter used to fit the element transfer function in time domain. Valid entries are:

  • "FIR" - Should be used where phase information is important
  • "IIR" - Can be used in cases where phase is not important but the transmission is frequency dependent
number_of_taps_estimation String

A string containing the method of choosing the number of taps for the FIR filter of the element. Valid entries are:

  • "group delay" - Chooses the number of FIR taps to match the expected group delay of the element, and allow the end user to use the delay compensation feature of INTERCONNECT
  • "fit tolerance" - Chooses the number of FIR taps to get the best match with the S-parameter spectrum.
  • "disabled" - Disables tap estimation and uses the number of 'fir_taps' provided by the user.
fir_taps Number

Number of taps for the FIR filter. Larger number allows to resolve frequency dependence better but increases time delay.

Suggestions:

  • Set to ~64 for devices where dispersive properties are important.
  • Set to ~1 for devices that will be used in circuits where time delays are a concern
 iir_taps  Number

Number of taps for infinite impulse response (IIR) filter.

Suggestions:

  • For most cases the default number of taps (4) is sufficient. In some cases it might be necessary to use a larger value
 passivity_enforcement  String

A string containing the method of passivity enforcement used on the input data. Valid entries are:

  • "ignore - Ignore any passivity issue in the data 
  • "test" - Tests if the induced 2-norm of the s-parameters is less than 1 in which case the data is passive.
  • "enforce" - Enforces the passivity by making sure the the induced 2-norm of the s-parameters is less than 1
 reciprocity_enforcement  String

A string containing the method of reciprocity enforcement used on the input data. Valid entries are:

  • "ignore - Ignore any reciprocity issue in the data 
  • "test" - Tests for symmetry across the diagonal of the s-parameter matrix in which case the data is reciprocal.
  • "enforce" - Enforces the symmetry across the diagonal of the s-parameter matrix.

Associated files

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