# # EDB: fully parametrized design # # 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 # # # + import os import tempfile import pyaedt import pyedb # - # ## Set non-graphical mode # # Set non-graphical mode. The default is ``False``, which opens # the AEDT UI. non_graphical = False # ## Launch EDB. # + temp_dir = tempfile.TemporaryDirectory(suffix=".ansys") aedb_path = os.path.join(temp_dir.name, "pcb.aedb") # Select EDB version (change it manually if needed, e.g. "2024.1") edb_version = "2024.1" print(f"EDB version: {edb_version}") edb = pyedb.Edb(edbpath=aedb_path, edbversion=edb_version) # - # Define the parameters. # + 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", "$corner_rad": "0.5mm", } for par_name in params: edb.add_project_variable(par_name, params[par_name]) # - # Define the stackup layers from bottom to top. layers = [ {"name": "bottom", "layer_type": "signal", "thickness": "35um", "material": "copper"}, {"name": "diel_3", "layer_type": "dielectric", "thickness": "275um", "material": "FR4_epoxy"}, {"name": "sig_2", "layer_type": "signal", "thickness": "35um", "material": "copper"}, {"name": "diel_2", "layer_type": "dielectric", "thickness": "275um", "material": "FR4_epoxy"}, {"name": "sig_1", "layer_type": "signal", "thickness": "35um", "material": "copper"}, {"name": "diel_1", "layer_type": "dielectric", "thickness": "275um", "material": "FR4_epoxy"}, {"name": "top", "layer_type": "signal", "thickness": "35um", "material": "copper"}, ] # Create the EDB stackup. # Define the bottom layer prev = None for layer in layers: edb.stackup.add_layer( layer["name"], base_layer=prev, layer_type=layer["layer_type"], thickness=layer["thickness"], material=layer["material"], ) prev = layer["name"] # Create a parametrized padstack for the signal via. signal_via_padstack = "automated_via" edb.padstacks.create( padstackname=signal_via_padstack, holediam="$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"], ) # Assign net names. There are only two signal nets. net_p = "p" net_n = "n" # Place the signal vias. 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, ) 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, ) 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, ) 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, ) # ## Draw parametrized traces # # Trace width and the routing (Microstrip-Stripline-Microstrip). # Applies to both p and n nets. # Trace width, n and p width = ["$ms_width", "$sl_width", "$ms_width"] # Routing layer, n and p route_layer = [layers[-1]["name"], layers[4]["name"], layers[-1]["name"]] # Define points for three traces in the "p" net points_p = [ [ ["0.0", "($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 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 + $ms_spacing)/2"], ], ] # Add traces to the EDB. trace_p = [] trace_n = [] for n in range(len(points_p)): trace_p.append(edb.modeler.create_trace(points_p[n], route_layer[n], width[n], net_p, "Flat", "Flat")) trace_n.append(edb.modeler.create_trace(points_n[n], route_layer[n], width[n], net_n, "Flat", "Flat")) # Create the wave ports edb.hfss.create_differential_wave_port( trace_p[0].id, ["0.0", "($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 + $ms_spacing)/2"], "wave_port_2", ) # Draw a conducting rectangle on the the ground layers. gnd_poly = [ [0.0, "-$pcb_w/2"], ["$pcb_len", "-$pcb_w/2"], ["$pcb_len", "$pcb_w/2"], [0.0, "$pcb_w/2"], ] gnd_shape = edb.modeler.Shape("polygon", points=gnd_poly) # Void in ground for traces on the signal routing layer # + void_poly = [ ["$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. # + 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. edb.nets.plot(None) # Save the EDB. edb.save_edb() edb.close_edb() # Open the project in HFSS 3D Layout. h3d = pyaedt.Hfss3dLayout( projectname=aedb_path, specified_version="2024.1", non_graphical=non_graphical, new_desktop_session=True, ) # ## Add HFSS simulation setup # # Add HFSS simulation setup. # + setup = h3d.create_setup() setup.props["AdaptiveSettings"]["SingleFrequencyDataList"]["AdaptiveFrequencyData"]["MaxPasses"] = 3 h3d.create_linear_count_sweep( setupname=setup.name, unit="GHz", freqstart=0, freqstop=10, num_of_freq_points=1001, sweepname="sweep1", sweep_type="Interpolating", interpolation_tol_percent=1, interpolation_max_solutions=255, save_fields=False, use_q3d_for_dc=False, ) # - # Define the differential pairs to used to calculate differential and common mode # s-parameters. h3d.set_differential_pair(diff_name="In", positive_terminal="wave_port_1:T1", negative_terminal="wave_port_1:T2") h3d.set_differential_pair(diff_name="Out", positive_terminal="wave_port_2:T1", negative_terminal="wave_port_2:T2") # Solve the project. h3d.analyze() # Plot the results and shut down AEDT. solutions = h3d.post.get_solution_data(["dB(S(In,In))", "dB(S(In,Out))"], context="Differential Pairs") solutions.plot() h3d.release_desktop() # 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. temp_dir.cleanup()