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Pre-layout Parameterized PCB#
This example shows how to use the EDB interface along with HFSS 3D Layout to create and solve a parameterized layout. The layout shows a differential via transition on a printed circuit board with back-to-back microstrip to stripline transitions. The model is fully parameterized to enable investigation of the transition performance on the many degrees of freedom.
The resulting model is shown below
Preparation#
Import the required packages
[1]:
import os
import tempfile
import time
from ansys.aedt.core import Hfss3dLayout
from pyedb import Edb
Define constants#
[2]:
AEDT_VERSION = "2025.2"
NUM_CORES = 4
NG_MODE = False # Open AEDT UI when it is launched.
Launch EDB#
[3]:
temp_folder = tempfile.TemporaryDirectory(suffix=".ansys")
aedb_path = os.path.join(temp_folder.name, "pcb.aedb")
edb = Edb(edbpath=aedb_path, edbversion=AEDT_VERSION)
C:\actions-runner\_work\pyaedt-examples\pyaedt-examples\.venv\lib\site-packages\pyedb\misc\decorators.py:55: UserWarning: Argument `edbversion` is deprecated for method `Edb`; use `version` instead.
warnings.warn(
C:\actions-runner\_work\pyaedt-examples\pyaedt-examples\.venv\lib\site-packages\pyedb\generic\design_types.py:301: UserWarning: Your ANSYS AEDT version is eligible to gRPC version.You might consider switching to that version for better user experience.For more information please check this link: https://edb.docs.pyansys.com/version/dev/grpc_api/index.html
warnings.warn(GRPC_GENERAL_WARNING, UserWarning)
PyEDB INFO: Star initializing Edb 05:36:40.713045
PyEDB INFO: Edb version 2025.2
PyEDB INFO: Logger is initialized. Log file is saved to C:\Users\ansys\AppData\Local\Temp\pyedb_ansys.log.
PyEDB INFO: legacy v0.60.0
PyEDB INFO: Python version 3.10.11 (tags/v3.10.11:7d4cc5a, Apr 5 2023, 00:38:17) [MSC v.1929 64 bit (AMD64)]
PyEDB INFO: create_edb completed in 8.6092 seconds.
PyEDB INFO: EDB C:\Users\ansys\AppData\Local\Temp\tmpv9sn1fuv.ansys\pcb.aedb created correctly.
PyEDB INFO: EDB initialization completed in 8.6725 seconds.
Create layout#
Define the parameters.#
[4]:
params = {
"$ms_width": "0.4mm",
"$sl_width": "0.2mm",
"$ms_spacing": "0.2mm",
"$sl_spacing": "0.1mm",
"$via_spacing": "0.5mm",
"$via_diam": "0.3mm",
"$pad_diam": "0.6mm",
"$anti_pad_diam": "0.7mm",
"$pcb_len": "15mm",
"$pcb_w": "5mm",
"$x_size": "1.2mm",
"$y_size": "1mm",
"$corner_rad": "0.5mm",
}
for par_name in params:
edb.add_project_variable(par_name, params[par_name])
Create stackup#
Define the stackup layers from bottom to top.
[5]:
layers = [
{
"name": "bottom",
"layer_type": "signal",
"thickness": "35um",
"material": "copper",
},
{
"name": "diel_3",
"layer_type": "dielectric",
"thickness": "275um",
"material": "FR4_epoxy",
},
{
"name": "sig_2",
"layer_type": "signal",
"thickness": "35um",
"material": "copper",
},
{
"name": "diel_2",
"layer_type": "dielectric",
"thickness": "275um",
"material": "FR4_epoxy",
},
{
"name": "sig_1",
"layer_type": "signal",
"thickness": "35um",
"material": "copper",
},
{
"name": "diel_1",
"layer_type": "dielectric",
"thickness": "275um",
"material": "FR4_epoxy",
},
{"name": "top", "layer_type": "signal", "thickness": "35um", "material": "copper"},
]
Define the bottom layer
[6]:
prev = None
for layer in layers:
edb.stackup.add_layer(
layer["name"],
base_layer=prev,
layer_type=layer["layer_type"],
thickness=layer["thickness"],
material=layer["material"],
)
prev = layer["name"]
Create a parametrized padstack for the signal via.#
Create a padstack definition.
[7]:
signal_via_padstack = "automated_via"
edb.padstacks.create(
padstackname=signal_via_padstack,
holediam="$via_diam",
paddiam="$pad_diam",
antipaddiam="",
antipad_shape="Bullet",
x_size="$x_size",
y_size="$y_size",
corner_radius="$corner_rad",
start_layer=layers[-1]["name"],
stop_layer=layers[-3]["name"],
)
PyEDB INFO: Padstack automated_via create correctly
[7]:
'automated_via'
Assign net names. There are only two signal nets.
[8]:
net_p = "p"
net_n = "n"
Place the signal vias.
[9]:
edb.padstacks.place(
position=["$pcb_len/3", "($ms_width+$ms_spacing+$via_spacing)/2"],
definition_name=signal_via_padstack,
net_name=net_p,
via_name="",
rotation=90.0,
)
[9]:
<pyedb.dotnet.database.edb_data.padstacks_data.EDBPadstackInstance at 0x21c153c4dc0>
[10]:
edb.padstacks.place(
position=["2*$pcb_len/3", "($ms_width+$ms_spacing+$via_spacing)/2"],
definition_name=signal_via_padstack,
net_name=net_p,
via_name="",
rotation=90.0,
)
[10]:
<pyedb.dotnet.database.edb_data.padstacks_data.EDBPadstackInstance at 0x21c153c7be0>
[11]:
edb.padstacks.place(
position=["$pcb_len/3", "-($ms_width+$ms_spacing+$via_spacing)/2"],
definition_name=signal_via_padstack,
net_name=net_n,
via_name="",
rotation=-90.0,
)
[11]:
<pyedb.dotnet.database.edb_data.padstacks_data.EDBPadstackInstance at 0x21c153c4c70>
[12]:
edb.padstacks.place(
position=["2*$pcb_len/3", "-($ms_width+$ms_spacing+$via_spacing)/2"],
definition_name=signal_via_padstack,
net_name=net_n,
via_name="",
rotation=-90.0,
)
[12]:
<pyedb.dotnet.database.edb_data.padstacks_data.EDBPadstackInstance at 0x21c153c45e0>
Draw parametrized traces#
Trace width and the routing (Microstrip-Stripline-Microstrip). Applies to both p and n nets.
[13]:
# Trace width, n and p
width = ["$ms_width", "$sl_width", "$ms_width"]
# Routing layer, n and p
route_layer = [layers[-1]["name"], layers[4]["name"], layers[-1]["name"]]
Define points for three traces in the “p” net
[14]:
points_p = [
[
["0.0", "($ms_width+$ms_spacing)/2"],
["$pcb_len/3-2*$via_spacing", "($ms_width+$ms_spacing)/2"],
["$pcb_len/3-$via_spacing", "($ms_width+$ms_spacing+$via_spacing)/2"],
["$pcb_len/3", "($ms_width+$ms_spacing+$via_spacing)/2"],
],
[
["$pcb_len/3", "($ms_width+$sl_spacing+$via_spacing)/2"],
["$pcb_len/3+$via_spacing", "($ms_width+$sl_spacing+$via_spacing)/2"],
["$pcb_len/3+2*$via_spacing", "($sl_width+$sl_spacing)/2"],
["2*$pcb_len/3-2*$via_spacing", "($sl_width+$sl_spacing)/2"],
["2*$pcb_len/3-$via_spacing", "($ms_width+$sl_spacing+$via_spacing)/2"],
["2*$pcb_len/3", "($ms_width+$sl_spacing+$via_spacing)/2"],
],
[
["2*$pcb_len/3", "($ms_width+$ms_spacing+$via_spacing)/2"],
["2*$pcb_len/3+$via_spacing", "($ms_width+$ms_spacing+$via_spacing)/2"],
["2*$pcb_len/3+2*$via_spacing", "($ms_width+$ms_spacing)/2"],
["$pcb_len", "($ms_width+$ms_spacing)/2"],
],
]
Define points for three traces in the “n” net
[15]:
points_n = [
[
["0.0", "-($ms_width+$ms_spacing)/2"],
["$pcb_len/3-2*$via_spacing", "-($ms_width+$ms_spacing)/2"],
["$pcb_len/3-$via_spacing", "-($ms_width+$ms_spacing+$via_spacing)/2"],
["$pcb_len/3", "-($ms_width+$ms_spacing+$via_spacing)/2"],
],
[
["$pcb_len/3", "-($ms_width+$sl_spacing+$via_spacing)/2"],
["$pcb_len/3+$via_spacing", "-($ms_width+$sl_spacing+$via_spacing)/2"],
["$pcb_len/3+2*$via_spacing", "-($ms_width+$sl_spacing)/2"],
["2*$pcb_len/3-2*$via_spacing", "-($ms_width+$sl_spacing)/2"],
["2*$pcb_len/3-$via_spacing", "-($ms_width+$sl_spacing+$via_spacing)/2"],
["2*$pcb_len/3", "-($ms_width+$sl_spacing+$via_spacing)/2"],
],
[
["2*$pcb_len/3", "-($ms_width+$ms_spacing+$via_spacing)/2"],
["2*$pcb_len/3 + $via_spacing", "-($ms_width+$ms_spacing+$via_spacing)/2"],
["2*$pcb_len/3 + 2*$via_spacing", "-($ms_width+$ms_spacing)/2"],
["$pcb_len", "-($ms_width + $ms_spacing)/2"],
],
]
Add traces to the EDB.
[16]:
trace_p = []
trace_n = []
for n in range(len(points_p)):
trace_p.append(
edb.modeler.create_trace(
points_p[n], route_layer[n], width[n], net_p, "Flat", "Flat"
)
)
trace_n.append(
edb.modeler.create_trace(
points_n[n], route_layer[n], width[n], net_n, "Flat", "Flat"
)
)
Create the wave ports
[17]:
edb.hfss.create_differential_wave_port(
trace_p[0].id,
["0.0", "($ms_width+$ms_spacing)/2"],
trace_n[0].id,
["0.0", "-($ms_width+$ms_spacing)/2"],
"wave_port_1",
)
edb.hfss.create_differential_wave_port(
trace_p[2].id,
["$pcb_len", "($ms_width+$ms_spacing)/2"],
trace_n[2].id,
["$pcb_len", "-($ms_width + $ms_spacing)/2"],
"wave_port_2",
)
[17]:
('wave_port_2',
<pyedb.dotnet.database.edb_data.ports.BundleWavePort at 0x21c153c7e50>)
Draw a conducting rectangle on the the ground layers.
[18]:
gnd_poly = [
[0.0, "-$pcb_w/2"],
["$pcb_len", "-$pcb_w/2"],
["$pcb_len", "$pcb_w/2"],
[0.0, "$pcb_w/2"],
]
gnd_shape = edb.modeler.Shape("polygon", points=gnd_poly)
Void in ground for traces on the signal routing layer
[19]:
void_poly = [
[
"$pcb_len/3",
"-($ms_width+$ms_spacing+$via_spacing+$anti_pad_diam)/2-$via_spacing/2",
],
[
"$pcb_len/3 + $via_spacing",
"-($ms_width+$ms_spacing+$via_spacing+$anti_pad_diam)/2-$via_spacing/2",
],
[
"$pcb_len/3 + 2*$via_spacing",
"-($ms_width+$ms_spacing+$via_spacing+$anti_pad_diam)/2",
],
[
"2*$pcb_len/3 - 2*$via_spacing",
"-($ms_width+$ms_spacing+$via_spacing+$anti_pad_diam)/2",
],
[
"2*$pcb_len/3 - $via_spacing",
"-($ms_width+$ms_spacing+$via_spacing+$anti_pad_diam)/2-$via_spacing/2",
],
[
"2*$pcb_len/3",
"-($ms_width+$ms_spacing+$via_spacing+$anti_pad_diam)/2-$via_spacing/2",
],
[
"2*$pcb_len/3",
"($ms_width+$ms_spacing+$via_spacing+$anti_pad_diam)/2+$via_spacing/2",
],
[
"2*$pcb_len/3 - $via_spacing",
"($ms_width+$ms_spacing+$via_spacing+$anti_pad_diam)/2+$via_spacing/2",
],
[
"2*$pcb_len/3 - 2*$via_spacing",
"($ms_width+$ms_spacing+$via_spacing+$anti_pad_diam)/2",
],
[
"$pcb_len/3 + 2*$via_spacing",
"($ms_width+$ms_spacing+$via_spacing+$anti_pad_diam)/2",
],
[
"$pcb_len/3 + $via_spacing",
"($ms_width+$ms_spacing+$via_spacing+$anti_pad_diam)/2+$via_spacing/2",
],
[
"$pcb_len/3",
"($ms_width+$ms_spacing+$via_spacing+$anti_pad_diam)/2+$via_spacing/2",
],
["$pcb_len/3", "($ms_width+$ms_spacing+$via_spacing+$anti_pad_diam)/2"],
]
void_shape = edb.modeler.Shape("polygon", points=void_poly)
Add ground conductors.
[20]:
for layer in layers[:-1:2]:
# add void if the layer is the signal routing layer.
void = [void_shape] if layer["name"] == route_layer[1] else []
edb.modeler.create_polygon(
main_shape=gnd_shape, layer_name=layer["name"], voids=void, net_name="gnd"
)
Plot the layout.
[21]:
edb.nets.plot(None)
PyEDB INFO: Plot Generation time 0.538
[21]:
(<Figure size 6000x3000 with 1 Axes>,
<Axes: title={'center': 'Edb Top View Cell_Z5YZ0I'}>)
Save the EDB.
[22]:
edb.save_edb()
edb.close_edb()
PyEDB INFO: Save Edb file completed in 0.0040 seconds.
PyEDB INFO: Close Edb file completed in 0.0066 seconds.
[22]:
True
Open the project in HFSS 3D Layout.#
[23]:
h3d = Hfss3dLayout(
project=aedb_path,
version=AEDT_VERSION,
non_graphical=NG_MODE,
new_desktop=True,
)
PyAEDT INFO: Python version 3.10.11 (tags/v3.10.11:7d4cc5a, Apr 5 2023, 00:38:17) [MSC v.1929 64 bit (AMD64)].
PyAEDT INFO: PyAEDT version 0.22.dev0.
PyAEDT INFO: Initializing new Desktop session.
PyAEDT INFO: Log on console is enabled.
PyAEDT INFO: Log on file C:\Users\ansys\AppData\Local\Temp\pyaedt_ansys_64a80f28-fa4f-46ae-8d43-2924b6cd9788.log is enabled.
PyAEDT INFO: Log on AEDT is disabled.
PyAEDT INFO: Debug logger is disabled. PyAEDT methods will not be logged.
PyAEDT INFO: Launching PyAEDT with gRPC plugin.
PyAEDT INFO: New AEDT session is starting on gRPC port 49540.
PyAEDT INFO: Electronics Desktop started on gRPC port: 49540 after 10.51261305809021 seconds.
PyAEDT INFO: AEDT installation Path C:\Program Files\ANSYS Inc\v252\AnsysEM
PyAEDT INFO: Ansoft.ElectronicsDesktop.2025.2 version started with process ID 8212.
PyAEDT INFO: EDB folder C:\Users\ansys\AppData\Local\Temp\tmpv9sn1fuv.ansys\pcb.aedb has been imported to project pcb
PyAEDT INFO: Active Design set to 0;Cell_Z5YZ0I
PyAEDT INFO: Active Design set to 0;Cell_Z5YZ0I
PyAEDT INFO: Aedt Objects correctly read
Add a HFSS simulation setup#
[24]:
setup = h3d.create_setup()
setup.props["AdaptiveSettings"]["SingleFrequencyDataList"]["AdaptiveFrequencyData"][
"MaxPasses"
] = 3
h3d.create_linear_count_sweep(
setup=setup.name,
unit="GHz",
start_frequency=0,
stop_frequency=10,
num_of_freq_points=1001,
name="sweep1",
sweep_type="Interpolating",
interpolation_tol_percent=1,
interpolation_max_solutions=255,
save_fields=False,
use_q3d_for_dc=False,
)
PyAEDT INFO: Parsing C:\Users\ansys\AppData\Local\Temp\tmpv9sn1fuv.ansys\pcb.aedt.
PyAEDT INFO: File C:\Users\ansys\AppData\Local\Temp\tmpv9sn1fuv.ansys\pcb.aedt correctly loaded. Elapsed time: 0m 0sec
PyAEDT INFO: aedt file load time 0.015688180923461914
PyAEDT INFO: Linear count sweep sweep1 has been correctly created.
[24]:
MySetupAuto : sweep1
Define the differential pairs to used to calculate differential and common mode s-parameters#
[25]:
h3d.set_differential_pair(
differential_mode="In", assignment="wave_port_1:T1", reference="wave_port_1:T2"
)
h3d.set_differential_pair(
differential_mode="Out", assignment="wave_port_2:T1", reference="wave_port_2:T2"
)
[25]:
True
Solve the project.
[26]:
h3d.analyze(cores=NUM_CORES)
PyAEDT INFO: Project pcb Saved correctly
PyAEDT INFO: Key Desktop/ActiveDSOConfigurations/HFSS 3D Layout Design correctly changed.
PyAEDT INFO: Solving all design setups. Analysis started...
PyAEDT INFO: Design setup None solved correctly in 0.0h 1.0m 53.0s
PyAEDT INFO: Key Desktop/ActiveDSOConfigurations/HFSS 3D Layout Design correctly changed.
[26]:
True
Plot the results and shut down AEDT.
[27]:
solutions = h3d.post.get_solution_data(
expressions=["dB(S(In,In))", "dB(S(In,Out))"], context="Differential Pairs"
)
solutions.plot()
PyAEDT INFO: Parsing C:\Users\ansys\AppData\Local\Temp\tmpv9sn1fuv.ansys\pcb.aedt.
PyAEDT INFO: File C:\Users\ansys\AppData\Local\Temp\tmpv9sn1fuv.ansys\pcb.aedt correctly loaded. Elapsed time: 0m 0sec
PyAEDT INFO: aedt file load time 0.026331663131713867
PyAEDT INFO: PostProcessor class has been initialized! Elapsed time: 0m 0sec
PyAEDT INFO: Post class has been initialized! Elapsed time: 0m 0sec
PyAEDT INFO: Loading Modeler.
PyAEDT INFO: Modeler loaded.
PyAEDT INFO: EDB loaded.
PyAEDT INFO: Layers loaded.
PyAEDT INFO: Primitives loaded.
PyAEDT INFO: Modeler class has been initialized! Elapsed time: 0m 0sec
PyEDB INFO: Star initializing Edb 05:39:17.913041
PyEDB INFO: Edb version 2025.2
PyEDB INFO: Logger is initialized. Log file is saved to C:\Users\ansys\AppData\Local\Temp\pyedb_ansys.log.
PyEDB INFO: legacy v0.60.0
PyEDB INFO: Python version 3.10.11 (tags/v3.10.11:7d4cc5a, Apr 5 2023, 00:38:17) [MSC v.1929 64 bit (AMD64)]
PyEDB INFO: Database pcb.aedb Opened in 2025.2
PyEDB INFO: Cell Cell_Z5YZ0I Opened
PyEDB INFO: Builder was initialized.
PyEDB INFO: open_edb completed in 0.0157 seconds.
PyEDB INFO: EDB initialization completed in 0.0316 seconds.
C:\actions-runner\_work\pyaedt-examples\pyaedt-examples\.venv\lib\site-packages\pyedb\generic\design_types.py:301: UserWarning: Your ANSYS AEDT version is eligible to gRPC version.You might consider switching to that version for better user experience.For more information please check this link: https://edb.docs.pyansys.com/version/dev/grpc_api/index.html
warnings.warn(GRPC_GENERAL_WARNING, UserWarning)
PyAEDT INFO: Solution Data Correctly Loaded.
Time to initialize solution data:0.03149056434631348
Time to initialize solution data:0.04758262634277344
[27]:
Release AEDT#
[28]:
h3d.save_project()
h3d.release_desktop()
# Wait 3 seconds to allow AEDT to shut down before cleaning the temporary directory.
time.sleep(3)
PyAEDT INFO: Project pcb Saved correctly
PyAEDT INFO: Desktop has been released and closed.
Note that the ground nets are only connected to each other due to the wave ports. The problem with poor grounding can be seen in the S-parameters. This example can be downloaded as a Jupyter Notebook, so you can modify it. Try changing parameters or adding ground vias to improve performance.
The final cell cleans up the temporary directory, removing all files.
[29]:
temp_folder.cleanup()
Download this example
Download this example as a Jupyter Notebook or as a Python script.