Optical time variant s-parameter element
Keywords
optical, bidirectional
Ports
| Name | Type |
|---|---|
| input | Electrical Signal |
| port 1 | Optical Signal |
| port 2 | Optical Signal |
Properties
General Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
name Defines the name of the element. |
Optical Time Variant S-Parameter | - | - |
|
annotate Defines whether or not to display annotations on the schematic editor. |
true | - | [true, false] |
|
enabled Defines whether or not the element is enabled. |
true | - | [true, false] |
|
type Defines the element unique type (read only). |
Optical Time Variant S-Parameter | - | - |
|
description A brief description of the elements functionality. |
Optical time variant s-parameter element | - | - |
|
prefix Defines the element name prefix. |
SPAR | - | - |
|
model Defines the element model name. |
- | - | - |
|
library Defines the element location or source in the library (custom or design kit). |
- | - | - |
|
local path Defines the local path or working folder $LOCAL for the element. |
- | - | - |
|
url An optional URL address pointing to the element online help. |
- | - | - |
Standard Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
configuration Defines the bidirectional or unidirectional element configuration. |
bidirectional | - | [bidirectional, s parameters |
|
load from file Defines whether or not to load s-parameters from an input file or to use the currently stored s-parameters. |
false | - | [true, false] |
|
s parameters filename The file containing the s-parameters. Refer to the Implementation Details section for the format expected. |
- | - | - |
Numerical Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
convert noise bins Defines if noise bins are incorporated into the signal waveform. |
true | - | [true, false] |
|
automatic seed Defines whether or not to automatically create an unique seed value for each instance of this element. The seed will be the same for each simulation run. |
true | - | [true, false] |
|
seed The value of the seed for the random number generator. A value zero recreates an unique seed for each simulation run. |
1 | - | [0, +∞) |
Numerical/Digital Filter Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
digital filter type Defines the digital filter type used to fit the element transfer function in time domain. |
FIR | - | [single tap, FIR, IIR |
|
number of taps estimation Defines the method used to estimate the number of taps of the digital filter. |
fit tolerance | - | [disabled, fit tolerance, group delay |
|
filter fit tolerance Defines the mean square error for the fitting function. |
0.05 | - | (0, 1) |
|
filter fit number of iterations This determines the maximum number of iterations required before fitting reaches the tolerance error. |
50 | - | [1, +∞) |
|
filter fit rolloff Defines the frequency roll off for the fitting function. |
0.05 | - | [0, 1) |
|
window function Defines the window type for the digital filter. |
rectangular | - | [rectangular, hamming, hanning |
|
number of fir taps Defines the number of coefficients for digital filter. |
256 | - | [1, +∞) |
|
maximum number of fir taps Defines the number of coefficients for digital filter. |
4096 | - | [1, +∞) |
|
filter delay Defines the time delay equivalent to a number of coefficients for digital filter. |
0 | s | [0, +∞) |
|
number of iir taps Defines the number of coefficients for digital filter. |
4 | - | [2, +∞) |
|
maximum number of iir taps Defines the number of coefficients for digital filter. |
20 | - | [2, +∞) |
|
initialize filter taps Defines whether to use the initial input signal to initialize filter state values or to set them to zero values. |
false | - | [true, false] |
Diagnostic Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
run diagnostic Enables the frequency response of the designed filter implementation and the ideal frequency response to be generated as results. |
false | - | [true, false] |
|
diagnostic size The number of frequency points used when calculating the filter frequency response. |
1024 | - | [2, +∞) |
Results
| Name | Description |
|---|---|
| diagnostic/response #/transmission | The complex transmission vs. frequency corresponding to the ideal and designed filter. |
| diagnostic/response #/gain | The gain vs. frequency corresponding to the ideal and designed filter. |
| diagnostic/response #/error | Mean square error comparing the frequency response of the designed filter implementation with the ideal frequency response. |
====================================
Implementation Details
The s-parameter file format for this element is shown below:
("output port name", "mode label", mode ID (out), "input port name", mode ID (in), "modulation")
(1, N)
a1, a2, ..., aN
(number of frequency points, 2*N+1)
f1 abs(S1) angle(S1) abs(S2) angle(S2) ... abs(SN) angle(SN)
f2 abs(S1) angle(S1) abs(S2) angle(S2) ... abs(SN) angle(SN)
...
An interpolation will be done among the time variant steps if no exact value is found in the file.
The Optical Time Variant S-Parameter is especially useful in modulator designs. It combines the frequency variant s-parameter with time variant signals so that can achieve a more realistic design of the modulators.
The example below ( electro-absorption_modulator.icp ) uses the Optical Time Variant S-Parameter element as a simple electro-absorption modulator and the plotted curves are the gain curves under different driving voltages.
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|
|
The data file loaded to the element ( electro-absorption_mod_spara.txt ) is partially listed below:
("port 2","TE",1,"port 1",1,"modulation")
(1,4)
0123
(100,9)
1.8737e+0140.35893900.26252900.2137500.1784770
1.87337e+0140.36591100.26682900.21692100.180740
1.87304e+0140.37177500.27037900.21947100.1825590
1.87271e+0140.37741900.27421100.22224100.1850160
1.87238e+0140.38311600.27807200.22502600.1873980
1.87205e+0140.391900.2837100.22882900.1892480
1.87172e+0140.39596300.28581500.22978700.1895980
1.87139e+0140.40022800.28841900.23174700.1915330
1.87106e+0140.40491500.29167100.2342900.1936740
1.87073e+0140.41025800.29541100.23727900.1963340
1.8704e+0140.4159100.29945100.24054700.1991440