Create openems_core_50ghz_mpa.py

modules/module_2_50GHz_MPA/part_4_layout_EMsims/core_1/openems/openems_core_50ghz_mpa.py

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+import os
+import sys
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), 'modules')))
+
+import modules.util_stackup_reader as stackup_reader
+import modules.util_gds_reader as gds_reader
+import modules.util_utilities as utilities
+import modules.util_simulation_setup as simulation_setup
+import modules.util_meshlines as util_meshlines
+
+import os
+import matplotlib.pyplot as plt  # pip install matplotlib
+import numpy as np
+from CSXCAD import ContinuousStructure
+from CSXCAD import AppCSXCAD_BIN
+from openEMS import openEMS
+from openEMS.physical_constants import *
+
+
+# Model comments
+# Changes for IHP Analog Academy in 01/2026:
+# Changed to MUR boundary at zmax so that radiation can be absorbed.
+# From experience, using MUR can create numerical issue when it touches the lossy silicon, so it is ONLY used at zmax.
+# All other boundaries use PEC, for best simulation speed.
+# Distance to side walls reduced, we have not much field there because of the Metal1 ground layout.
+
+# This model uses an alternative syntax where are settings are stored in settings dictionary,
+# which makes it easier to implement future extensions without touching again the 
+# simulation model code
+
+
+# ======================== workflow settings ================================
+settings = {}
+
+settings['preview_only'] = False  # @brief Enable this to preview model/mesh only, without starting simulation
+settings['postprocess_only'] = False # @brief Enable this to show existing results only, without starting simulation
+
+# ===================== input files and path settings =======================
+
+# GDS filename
+gds_filename = "../layout_gds/50_ghz_mpa_core_no_BJT.gds"      # geometries
+XML_filename = "SG13G2.xml"       # stackup
+
+settings['purpose'] = [0] # @brief Which GDSII data type is evaluated? Values in [] can be separated by comma
+settings['preprocess_gds'] = False  # @brief  Preprocess GDSII for safe handling of cutouts/holes?
+settings['merge_polygon_size'] = 0.5 #  @brief  Merge via polygons with distance less than .. microns, set to 0 to disable via merging.
+
+# get path for this simulation file
+script_path = utilities.get_script_path(__file__)
+
+# use script filename as model basename
+model_basename = utilities.get_basename(__file__)
+
+# set and create directory for simulation output
+sim_path = utilities.create_sim_path (script_path,model_basename)
+print('Simulation data directory: ', sim_path)
+
+
+# ======================== simulation settings ================================
+
+
+settings['unit']   = 1e-06  # @brief Geometry units, 1E-6 is in microns
+settings['margin'] = 20    # @brief Distance from GDSII geometry boundary to simulation boundary, in project units 
+
+settings['fstart']   = 0e9  # @brief start frequency [Hz]
+settings['fstop']    = 350e9 # @brief stop frequency [Hz]
+settings['numfreq']  = 401  # @brief number of frequency steps [Hz]
+
+settings['refined_cellsize'] = 0.5  # @brief mesh cell size in conductor region, in project units
+
+# choices for boundary:
+# 'PEC' : perfect electric conductor (default)
+# 'PMC' : perfect magnetic conductor, useful for symmetries
+# 'MUR' : simple MUR absorbing boundary conditions
+# 'PML_8' : PML absorbing boundary conditions
+settings['Boundaries'] = ['PEC', 'PEC', 'PEC', 'PEC', 'PEC', 'MUR']
+
+settings['cells_per_wavelength'] = 20   # @brief how many mesh cells per wavelength, must be 10 or more
+settings['energy_limit'] = -50          # @brief end criteria for residual energy (dB), default is -40
+
+
+# ports from GDSII Data, polygon geometry from specified special layer
+# note that for multiport simulation, excitations are switched on/off in simulation_setup.createSimulation below
+simulation_ports = simulation_setup.all_simulation_ports()
+# instead of in-plane port specified with target_layername, we here use via port specified with from_layername and to_layername. GND means bottom of simulation box
+simulation_ports.add_port(simulation_setup.simulation_port(portnumber=1, voltage=1, port_Z0=50, source_layernum=201, from_layername='Metal3', to_layername='TopMetal2', direction='z'))
+simulation_ports.add_port(simulation_setup.simulation_port(portnumber=2, voltage=1, port_Z0=50, source_layernum=202, from_layername='Metal3', to_layername='TopMetal2', direction='z'))
+simulation_ports.add_port(simulation_setup.simulation_port(portnumber=3, voltage=1, port_Z0=50, source_layernum=203, target_layername='Metal2', direction='-x'))
+simulation_ports.add_port(simulation_setup.simulation_port(portnumber=4, voltage=1, port_Z0=50, source_layernum=204, target_layername='Metal2', direction='x'))
+
+# ======================== simulation ================================
+
+# get technology stackup data
+materials_list, dielectrics_list, metals_list = stackup_reader.read_substrate (XML_filename)
+# get list of layers from technology
+layernumbers = metals_list.getlayernumbers()
+layernumbers.extend(simulation_ports.portlayers)
+
+# read geometries from GDSII, only purpose 0
+allpolygons = gds_reader.read_gds(gds_filename,
+                                  layernumbers,
+                                  purposelist=settings['purpose'],
+                                  metals_list=metals_list,
+                                  preprocess=settings['preprocess_gds'],
+                                  merge_polygon_size=settings['merge_polygon_size'])
+
+
+########### create model, run and post-process ###########
+
+settings['simulation_ports'] = simulation_ports
+settings['materials_list'] = materials_list
+settings['dielectrics_list'] = dielectrics_list
+settings['metals_list'] = metals_list
+settings['layernumbers'] = layernumbers
+settings['allpolygons'] = allpolygons
+settings['sim_path'] = sim_path
+settings['model_basename'] = model_basename
+
+# define excitation and stop criteria and boundaries
+FDTD = openEMS(EndCriteria=np.exp(settings['energy_limit']/10 * np.log(10)))
+FDTD.SetGaussExcite((settings['fstart'] + settings['fstop'])/2,
+                    (settings['fstop'] - settings['fstart'])/2)
+FDTD.SetBoundaryCond(settings['Boundaries'])
+
+
+########### create model, run and post-process ###########
+
+# run all port excitations, one after another
+for port in simulation_ports.ports:
+    settings['excite_portnumbers'] = [port.portnumber]
+
+    # prepare model from GDSII data
+    simulation_setup.setupSimulation(FDTD=FDTD, settings=settings)  # must use named parameters when using settings dict!
+
+    # preview model and start simulation
+    simulation_setup.runSimulation(FDTD=FDTD, settings=settings)    # must use named parameters when using settings dict!
+
+
+# Initialize an empty matrix for S-parameters
+num_ports = simulation_ports.portcount
+s_params = np.empty((num_ports, num_ports, settings['numfreq']), dtype=object)
+
+# Define frequency resolution (postprocessing)
+f = np.linspace(settings['fstart'], settings['fstop'], settings['numfreq'])
+
+# Populate the S-parameter matrix with simulation results
+for i in range(1, num_ports + 1):
+    for j in range(1, num_ports + 1):
+        s_params[i-1, j-1] = utilities.calculate_Sij(i, j, f, sim_path, simulation_ports)
+
+# Write to Touchstone *.snp file
+snp_name = os.path.join(sim_path, model_basename + '.s' + str(num_ports) + 'p')
+utilities.write_snp(s_params, f, snp_name)
+
+print('Created S-parameter output file at ', snp_name)