Microstrip

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=1000, width=14)

r = c.get_region(layer=LAYER.TopMetal2drawing)
r_sized = r.sized(+20000)
c.add_polygon(r_sized, layer=LAYER.Metal1drawing)


c.add_ports(r1.ports)

cc = c.copy()
cc.draw_ports()
cc

png

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=80)

# Validate configuration
print(sim.validate_config())

Validation: PASSED

# Generate mesh (presets: "coarse", "default", "fine")
sim.mesh(preset="default")

Warning : 7 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: 1140.0 x 154.0 x 318.3 µm
Nodes:      6,220
Elements:   46,925
Tetrahedra: 33,285
Edge length: 0.40 - 285.00 µm
Quality:    0.391 (min: 0.001)
SICN:       0.430 (all valid)
----------------------------------------
Volumes (3):
  - SiO2 [1]
  - passive [2]
  - air [3]
Surfaces (11):
  - metal1_xy [4]
  - metal1_z [5]
  - topmetal2_xy [6]
  - topmetal2_z [7]
  - P1 [8]
  - P2 [9]
  - SiO2__None [10]
  - SiO2__passive [11]
  - passive__None [12]
  - air__passive [13]
  - air__None [14]
----------------------------------------
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)

png

Run simulation on GDSFactory+ Cloud¶

# Run simulation on GDSFactory+ cloud
results = sim.run()

  palace-cc1d6438  completed  2m 31s


Extracting results.tar.gz...
Downloaded 6 files to /home/runner/work/gsim/gsim/nbs/sim-data-palace-cc1d6438

import matplotlib.pyplot as plt
import pandas as pd

df = pd.read_csv(results["port-S.csv"])
df.columns = df.columns.str.strip()

freq = df["f (GHz)"]

fig, axes = plt.subplots(2, 2, figsize=(8, 5))

# S11 Magnitude
axes[0, 0].plot(freq, df["|S[1][1]| (dB)"], marker=".")
axes[0, 0].set_xlabel("Frequency (GHz)")
axes[0, 0].set_ylabel("Magnitude (dB)")
axes[0, 0].set_title("S11 Magnitude")
axes[0, 0].grid(True)

# S21 Magnitude
axes[0, 1].plot(freq, df["|S[2][1]| (dB)"], marker=".", color="tab:orange")
axes[0, 1].set_xlabel("Frequency (GHz)")
axes[0, 1].set_ylabel("Magnitude (dB)")
axes[0, 1].set_title("S21 Magnitude")
axes[0, 1].grid(True)

# S11 Phase
axes[1, 0].plot(freq, df["arg(S[1][1]) (deg.)"], marker=".")
axes[1, 0].set_xlabel("Frequency (GHz)")
axes[1, 0].set_ylabel("Phase (deg)")
axes[1, 0].set_title("S11 Phase")
axes[1, 0].grid(True)

# S21 Phase
axes[1, 1].plot(freq, df["arg(S[2][1]) (deg.)"], marker=".", color="tab:orange")
axes[1, 1].set_xlabel("Frequency (GHz)")
axes[1, 1].set_ylabel("Phase (deg)")
axes[1, 1].set_title("S21 Phase")
axes[1, 1].grid(True)

plt.tight_layout()

png