A statistically enabled electro-optic phase shifter model based on free-carrier plasma dispersion effects. This device is assumed to be composed of an active region in the middle, connected to the input/output ports by passive transitions and waveguides. For a diagram of the expected layout, see the Internal Model Diagram in photonic model page.
The statistical parameters are delta_width, delta_height, delta_ridge_height, delta_Vpi_Lpi, and delta_IL.
For information on statistical CMLs, see Statistical CMLs.
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Electrical Phase Shifter (Statistical) - Lumfoundry Template
Template: ps_pn_stat_te_c (lumped model)
Photonic Model: phase_shifter_electrical
Quality Assurance Test: phase_shifter_electrical QA
Statistically Enabled Parameters: neff (active wg), ng (active wg), Vpi_Lpi, and IL
Parameters: length of the active region
Virtuoso/Verilog-A Support: Yes
Required Data
Parameter Script File
[[snippet||7228384629395]]
lock_Vpi_Lpi |
Boolean |
Enable/disable tuning of the Vpi_Lpi (V-m) of the phase shifter. Note:
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QA Variables
[[snippet||7227146485523]]
Vpi_Lpi_rel_tolerance | Number |
Relative tolerance for QA tests which verify the model properties. If the simulated values differ from the values provided within the data file by more than this tolerance, the QA tests will fail. |
* Note: BW_test_bias is typically set at half Vpi of the phase shifter with default length.
Statistical QA Variables (statistical compact models only)
[[snippet||7227654825107]]
stat_Vpi_Lpi_tolerance | Number | Absolute tolerance for QA tests which verify the statistical variations of the mode properties. If the simulated values differ from the values provided within the data file by more than this tolerance, the QA tests will fail. |
Data File
Nominal Data
[[snippet||7229114568851]]
electrical_bandwidth_data |
Matrix |
N x 2 matrix containing the 3-dB cutoff frequency (Hz) of the electrical modulator as a function of bias voltage (V), where N is the number of bias points, and the columns contain:
Notes:
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phase_shifter_data |
Cell |
M x 1 cell array containing structs which describe the variation of the effective index within the active region, as a function of bias voltage (V). Each element of the cell array is a struct containing the following fields:
Notes:
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Model Tuning & QA Data
This data is required for CML Compiler to run quality-assurance tests on the final model. It is also optionally used by CML Compiler to fine-tune the internal model to provide the expected behavior.
Variable | Type | Description |
---|---|---|
IL |
Struct
|
The total insertion loss (dB) of the phase shifter at zero bias provided as a struct. The struct has the following fields:
Notes:
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Vpi_Lpi |
Large signal Vpi.Lpi (V-m) of the electrical phase shifter (as explained in the Vpi Data Visualization in photonic model page section) for voltages between Vpi_Lpi_voltage1 and Vpi_Lpi_voltage2 provided as a struct. The struct has the following fields:
Notes:
|
|
Vpi_Lpi_voltage1 |
Matrix
|
M x 1 matrix containing the lower limit of the bias voltage for which the Vpi_Lpi values are valid, where M is the number of modes. |
Vpi_Lpi_voltage2 |
M x 1 matrix containing the upper limit of the bias voltage for which the Vpi_Lpi values are valid, where M is the number of modes. |
Electrical Phase Shifter Data
In order to model the electrical phase shifter, either a travelling wave model or a lumped model may be used. This particular template uses a lumped model which is defined within the parameter .lsf file:
use_travelling_wave_electrode = false;
To learn about how to model a traveling wave electrode check the Electrical Phase Shifter - Lumfoundry Template page.
The data within this section is used to construct an electrical equivalent circuit which captures the bandwidth of the electrical phase shifters. For more information on this equivalent circuit, see Electrical Equivalent Circuit in photonic model page.
Variable | Type | Description |
---|---|---|
Cj |
Matrix |
N x 2 matrix containing the junction capacitance (F/m) of the electrical phase shifter, where N is the number of bias points, and the columns contain:
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Rj |
Number
|
Junction resistance (Ohm.m) of the phase shifter |
Rp |
Contact resistance (Ohm) of the metal pad |
|
Cp |
Parasitic capacitance (F) between metal pads |
Statistical Data (optional)
This data is required for CML Compiler to enable statistical modeling. Note that to allow CML Compiler to build statistically enabled models, the statistical_parameter_status has to be defined in the XML file. For more information, see Statistical CMLs.
Variable | Type | Description |
---|---|---|
stat_parameters |
Cell |
A cell of length N containing the statistical data for the ring modulator where N is the number of statistical parameters. Each entry in the cell is a struct with the following fields. |
stat_parameters{i}.name |
String |
Name of the i-th statistical parameter. |
stat_parameters{i}.mean |
Number |
Mean value of the i-th statistical parameter. |
stat_parameters{i}.corners |
Matrix |
Corner values for the i-th statistical parameter provides as an Cx1 matrix where C is the number of process corners defined in the XML file. Note: The values for the process corners should follow the same order as in the XML file. |
stat_parameters{i}.slope_neff |
Number
|
The sensitivity of the effective index of the active waveguide with respect to the i-th statistical parameter defined as d_neff / d_stat_parameters{i}. Note: Only provide this field if the statistical parameter affects the effective index (see ps_pn_stat_te_c). |
stat_parameters{i}.slope_ng |
The sensitivity of the group index of the active waveguide with respect to the i-th statistical parameter defined as d_ng / d_stat_parameters{i}. Note: Only provide this field if the statistical parameter affects the group index (see ps_pn_stat_te_c). |
|
stat_parameters{i}.slope_Vpi_Lpi |
The sensitivity of the Vpi_Lpi (V-m) of the electrical phase shifter with respect to the i-th statistical parameter defined as d_Vpi_Lpi / d_stat_parameters{i}. Note: Only provide this field if the statistical parameter affects the Vpi_Lpi (see ps_pn_stat_te_c). |
|
stat_parameters{i}.slope_IL |
The sensitivity of the insertion loss (dB) of the electrical phase shifter with respect to the i-th statistical parameter defined as d_IL / d_stat_parameters{i}. Note: Only provide this field if the statistical parameter affects the insertion loss (see ps_pn_stat_te_c). |
|
stat_parameters{i}.LOCAL |
Struct
|
A struct describing the LOCAL level variation of the i-th statistical parameter with the following fields: distribution = Defines the type of the PDF used to describe the LOCALlevel variation. Currently the options are 'normal' (Gaussian) or 'pearson4' (Non-Gaussian). sigma = The standard deviation of the LOCAL level variation. gamma1: The skewness of the LOCAL level variation (for pearson4 distribution only) beta2: The kurtosis of the LOCAL level variation (for pearson4 distribution only) |
stat_parameters{i}.GLOBAL |
A struct containing the GLOBAL level variation of the i-th statistical parameter with the following fields: distribution = Defines the type of the PDF used to describe the GLOBAL level variation. Currently the options are 'normal' (Gaussian) or 'pearson4' (Non-Gaussian). sigma = The standard deviation of the GLOBAL level variation. gamma1: The skewness of the GLOBAL level variation (for pearson4 distribution only) beta2: The kurtosis of the GLOBAL level variation (for pearson4 distribution only) GLOBALGROUP : Name of the GLOBALGROUP defined in the top level XML file. (if a GLOBALGROUP is provided then the description in the XML file takes priority over the data file) NOTE: It is optional to provide a GLOBAL level variation for statistical parameters. |