Palace Width Sweep: Parallel Simulation¶

Sweep the microstrip width from 5 to 50 um (5 points), run all simulations in parallel on GDSFactory+ cloud using the non-blocking API, then compare S11 and S21 across widths.

Requirements:

IHP PDK: uv pip install ihp-gdsfactory
GDSFactory+ account for cloud simulation

Define the sweep¶

import numpy as np

widths = np.arange(2, 21, 4)

Build components and configure simulations¶

import gdsfactory as gf
from ihp import LAYER, PDK, cells

from gsim.common.stack import get_stack
from gsim.palace import DrivenSim

PDK.activate()

stack = get_stack()  # auto-detects active PDK

sims = []

for w in widths:
    # Build component
    c = gf.Component()
    r1 = c << cells.straight_metal(length=1000, width=w)

    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)

    # Configure simulation
    sim = DrivenSim()
    sim.set_output_dir(f"./palace-sim-w{w:.1f}")
    sim.set_geometry(c)
    sim.set_stack(stack)
    # Surround the design with air. Without this the absorbing boundary sits
    # directly on the passivation, microns above the trace, and adds large
    # spurious loss and reflection.
    sim.set_airbox(margin_x=50, margin_y=50, z_above=100, z_below=100)

    for port in c.ports:
        sim.add_port(
            port.name, from_layer="metal1", to_layer="topmetal2", geometry="interlayer"
        )

    sim.set_driven(fmin=1e9, fmax=100e9, num_points=80)
    sim.mesh(preset="default")

    sims.append(sim)

print(f"Configured {len(sims)} simulations")

pyvirtualdisplay not available; continuing without Xvfb


Small conductor feature detected (2.000 um) may be under-resolved by refined_mesh_size=5.000 um. Pass auto_size=True to scale the mesh down.


Configured 5 simulations

Upload and start all jobs (non-blocking)¶

# Upload and start all jobs without waiting
job_ids = []
for sim in sims:
    job_id = sim.run(wait=False, check_cache=True)
    job_ids.append(job_id)

print(f"Started {len(job_ids)} jobs: {job_ids}")

Info    : Reading 'palace-sim-w2.0/palace.msh'...
Info    : 9203 nodes
Info    : 69098 elements
Info    : Done reading 'palace-sim-w2.0/palace.msh'
Info    : Reading 'palace-sim-w2.0/palace.msh'...
Info    : 9203 nodes
Info    : 69098 elements
Info    : Done reading 'palace-sim-w2.0/palace.msh'


Cache hit: reusing job 01a0f822-34d5-7fe3-b8e3-5d9fe8b3670e
Info    : Reading 'palace-sim-w6.0/palace.msh'...
Info    : 9838 nodes
Info    : 74046 elements
Info    : Done reading 'palace-sim-w6.0/palace.msh'
Info    : Reading 'palace-sim-w6.0/palace.msh'...
Info    : 9838 nodes
Info    : 74046 elements
Info    : Done reading 'palace-sim-w6.0/palace.msh'


Cache hit: reusing job 01a0f822-3ae8-7633-beef-bb96ec13bfdb
Info    : Reading 'palace-sim-w10.0/palace.msh'...
Info    : 9784 nodes
Info    : 73826 elements
Info    : Done reading 'palace-sim-w10.0/palace.msh'
Info    : Reading 'palace-sim-w10.0/palace.msh'...
Info    : 9784 nodes
Info    : 73826 elements
Info    : Done reading 'palace-sim-w10.0/palace.msh'


Cache hit: reusing job 01a0f822-41e6-7c51-9015-cbe238d204db
Info    : Reading 'palace-sim-w14.0/palace.msh'...
Info    : 9643 nodes
Info    : 72801 elements
Info    : Done reading 'palace-sim-w14.0/palace.msh'
Info    : Reading 'palace-sim-w14.0/palace.msh'...
Info    : 9643 nodes
Info    : 72801 elements
Info    : Done reading 'palace-sim-w14.0/palace.msh'


Cache hit: reusing job 01a0f822-47cb-7600-88ff-0bdf0d991b1d
Info    : Reading 'palace-sim-w18.0/palace.msh'...
Info    : 9918 nodes
Info    : 74998 elements
Info    : Done reading 'palace-sim-w18.0/palace.msh'
Info    : Reading 'palace-sim-w18.0/palace.msh'...
Info    : 9918 nodes
Info    : 74998 elements
Info    : Done reading 'palace-sim-w18.0/palace.msh'


Cache hit: reusing job 01a0f822-4ddd-71a3-a549-8f617d822423
Started 5 jobs: ['01a0f822-34d5-7fe3-b8e3-5d9fe8b3670e', '01a0f822-3ae8-7633-beef-bb96ec13bfdb', '01a0f822-41e6-7c51-9015-cbe238d204db', '01a0f822-47cb-7600-88ff-0bdf0d991b1d', '01a0f822-4ddd-71a3-a549-8f617d822423']

Wait for all jobs to complete¶

import gsim

# Poll all jobs concurrently, download and parse results
results = gsim.wait_for_results(job_ids)

Waiting for 5 jobs...
  palace-5b5227f5                [####################] 100% complete     elapsed 0m 00s
  palace-37990c45                [####################] 100% complete     elapsed 0m 00s
  palace-2a9da1de                [####################] 100% complete     elapsed 0m 00s
  palace-1215f504                [####################] 100% complete     elapsed 0m 00s
  palace-f9f6ddc2                [####################] 100% complete     elapsed 0m 00s


Extracting results.tar.gz...
Downloaded 12 files to sim-data-palace-5b5227f5


Extracting results.tar.gz...
Downloaded 12 files to sim-data-palace-37990c45


Extracting results.tar.gz...
Downloaded 12 files to sim-data-palace-2a9da1de


Extracting results.tar.gz...
Downloaded 12 files to sim-data-palace-1215f504


Extracting results.tar.gz...
Downloaded 12 files to sim-data-palace-f9f6ddc2

Plot S11 and S21 comparison¶

import matplotlib.pyplot as plt

fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(6, 6))

for w, sp in zip(widths, results, strict=True):
    ax1.plot(sp.freq, sp.s11.db, label=f"w={w:.1f} um")
    ax2.plot(sp.freq, sp.s21.db, label=f"w={w:.1f} um")

ax1.set(
    xlabel="Frequency (GHz)", ylabel="|S11| (dB)", title="S11 — Return Loss vs Width"
)
ax1.legend()
ax1.grid(True)

ax2.set(
    xlabel="Frequency (GHz)", ylabel="|S21| (dB)", title="S21 — Insertion Loss vs Width"
)
ax2.legend()
ax2.grid(True)

plt.tight_layout()

png