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 CPW (coplanar waveguide) structure.
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
PDK.activate()
@gf.cell
def gsg_electrode(
length: float = 800,
s_width: float = 20,
g_width: float = 40,
gap_width: float = 15,
layer=LAYER.TopMetal2drawing,
) -> gf.Component:
"""
Create a GSG (Ground-Signal-Ground) electrode.
Args:
length: horizontal length of the electrodes
s_width: width of the signal (center) electrode
g_width: width of the ground electrodes
gap_width: gap between signal and ground electrodes
layer: layer for the metal
"""
c = gf.Component()
# Top ground electrode
r1 = c << gf.c.rectangle((length, g_width), centered=True, layer=layer)
r1.move((0, (g_width + s_width) / 2 + gap_width))
# Center signal electrode
_r2 = c << gf.c.rectangle((length, s_width), centered=True, layer=layer)
# Bottom ground electrode
r3 = c << gf.c.rectangle((length, g_width), centered=True, layer=layer)
r3.move((0, -(g_width + s_width) / 2 - gap_width))
# Add ports at the signal center (one per side)
# The CPW port API computes the gap element surfaces from s_width and gap_width
c.add_port(
name="o1",
center=(-length / 2, 0),
width=s_width,
orientation=0,
port_type="electrical",
layer=layer,
)
c.add_port(
name="o2",
center=(length / 2, 0),
width=s_width,
orientation=180,
port_type="electrical",
layer=layer,
)
return c
c = gsg_electrode()
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-cpw")
# 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 left CPW port (single port at signal center)
sim.add_cpw_port("o1", layer="topmetal2", s_width=20, gap_width=15)
# Configure right CPW port (single port at signal center)
sim.add_cpw_port("o2", layer="topmetal2", s_width=20, gap_width=15)
# Configure driven simulation (frequency sweep for S-parameters)
sim.set_driven(fmin=1e9, fmax=100e9, num_points=300)
# Validate configuration
print(sim.validate_config())
Validation: PASSED
# Generate mesh with planar conductors (presets: "coarse", "default", "fine")
sim.mesh(preset="default", planar_conductors=False)
Warning : 3 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: 900.0 x 230.0 x 318.3 µm
Nodes: 9,635
Elements: 74,228
Tetrahedra: 54,210
Edge length: 0.05 - 300.00 µm
Quality: 0.452 (min: 0.000)
SICN: 0.501 (all valid)
----------------------------------------
Volumes (3):
- SiO2 [1]
- passive [2]
- air [3]
Surfaces (11):
- topmetal2_xy [4]
- topmetal2_z [5]
- P1_E0 [6]
- P1_E1 [7]
- P2_E0 [8]
- P2_E1 [9]
- SiO2__None [10]
- SiO2__passive [11]
- passive__None [12]
- air__passive [13]
- air__None [14]
----------------------------------------
Mesh: palace-sim-cpw/palace.msh
/home/runner/work/gsim/gsim/src/gsim/viz.py:261: UserWarning: Failed to use notebook backend:
Please install `nest_asyncio2` to automagically launch the trame server without await. Or, to avoid `nest_asyncio2` run:
from pyvista.trame.jupyter import launch_server
await launch_server().ready
Falling back to a static output.
plotter.show()
Run simulation on cloud¶
palace-fc5f47a7 completed 10m 34s
Extracting results.tar.gz...
Downloaded 10 files to /home/runner/work/gsim/gsim/nbs/sim-data-palace-fc5f47a7