Palace is an open-source 3D electromagnetic simulator supporting eigenmode, driven (S-parameter), and electrostatic simulations. This notebook demonstrates using the gsim.palace API to run a driven simulation on a microstrip transmission line with via ports.
Requirements:
- IHP PDK:
uv pip install ihp-gdsfactory - GDSFactory+ account for cloud simulation
Load a pcell from IHP PDK¶
import gdsfactory as gf
from ihp import LAYER, PDK, cells
PDK.activate()
c = gf.Component()
r1 = c << cells.straight_metal(length=200, width=15)
r = c.get_region(layer=LAYER.TopMetal2drawing)
r_sized = r.sized(+50000)
c.add_polygon(r_sized, layer=LAYER.Metal1drawing)
c.add_ports(r1.ports)
cc = c.copy()
cc.draw_ports()
cc
Configure and run simulation with DrivenSim¶
from gsim.palace import DrivenSim
# Create simulation object
sim = DrivenSim()
# Set output directory
sim.set_output_dir("./palace-sim-microstrip")
# Set the component geometry
sim.set_geometry(c)
# Configure layer stack from active PDK
sim.set_stack(substrate_thickness=2.0, air_above=300.0)
# Configure via ports (Metal1 ground plane to TopMetal2 signal)
for port in c.ports:
sim.add_port(port.name, from_layer="metal1", to_layer="topmetal2", geometry="via")
# Configure driven simulation (frequency sweep for S-parameters)
sim.set_driven(fmin=1e9, fmax=100e9, num_points=40)
# Validate configuration
print(sim.validate_config())
Validation: PASSED
Warning : 43 ill-shaped tets are still in the mesh
Warning : ------------------------------
Warning : Mesh generation error summary
Warning : 1 warning
Warning : 0 errors
Warning : Check the full log for details
Warning : ------------------------------
Mesh Summary
========================================
Dimensions: 500.0 x 315.0 x 416.6 µm
Nodes: 2,613
Elements: 20,559
Tetrahedra: 14,757
Edge length: 0.40 - 327.46 µm
Quality: 0.394 (min: 0.001)
SICN: 0.440 (all valid)
----------------------------------------
Volumes (4):
- air [1]
- passive [2]
- SiO2 [3]
- airbox [4]
Surfaces (7):
- metal1_xy [5]
- metal1_z [6]
- topmetal2_xy [7]
- topmetal2_z [8]
- P1 [9]
- P2 [10]
- Absorbing_boundary [11]
----------------------------------------
Mesh: palace-sim-microstrip/palace.msh
# Static PNG
sim.plot_mesh(show_groups=["metal", "P"], interactive=False)
# Interactive
# sim.plot_mesh(show_groups=["metal", "P"], interactive=True)
PosixPath('palace-sim-microstrip/config.json')
Run simulation on GDSFactory+ Cloud¶
Uploading simulation...
done
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Created: 21:44:42 | Now: 21:45:45 | Status: completed Extracting results.tar.gz... Downloaded 6 files to /home/runner/work/gsim/gsim/nbs/sim-data-palace-f4aa3c12/results/palace
import matplotlib.pyplot as plt
import pandas as pd
df = pd.read_csv(results["port-S.csv"])
df.columns = df.columns.str.strip() # Remove whitespace from column names
freq = df["f (GHz)"]
fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(6, 6))
# Magnitude plot
ax1.plot(freq, df["|S[1][1]| (dB)"], marker=".", label="S11")
ax1.plot(freq, df["|S[2][1]| (dB)"], marker=".", label="S21")
ax1.set_xlabel("Frequency (GHz)")
ax1.set_ylabel("Magnitude (dB)")
ax1.set_title("S-Parameters")
ax1.legend()
ax1.grid(True)
# Phase plot
ax2.plot(freq, df["arg(S[1][1]) (deg.)"], marker=".", label="S11")
ax2.plot(freq, df["arg(S[2][1]) (deg.)"], marker=".", label="S21")
ax2.set_xlabel("Frequency (GHz)")
ax2.set_ylabel("Phase (deg)")
ax2.legend()
ax2.grid(True)
plt.tight_layout()
