Low DifferentialPair Impedance value on examples. #26
Description
Hi there,
I am not sure the results I am getting are right. I have tried a fresh install of both openEMS and gerber2ems, however the "differential" example appears to yield fairly low impedance values when running gerber2ems -a
Please note that my reference is this here: https://openhardware.antmicro.com/boards/si-simulation-test-board/?si-track-id=SHORT+STUB&tab=simulation
Any help would be greatly appreciated.
/home/user-name/.local/share/pipx/venvs/gerber2ems/lib/python3.12/site-packages/matplotlib/projections/__init__.py:63: UserWarning: Unable to import Axes3D. This may be due to multiple versions of Matplotlib being installed (e.g. as a system package and as a pip package). As a result, the 3D projection is not available.
warnings.warn("Unable to import Axes3D. This may be due to multiple versions of "
Parsing config
Loading config from /home/user-name/gerber2ems/examples/differential/simulation.json
[20:27:32][INFO] Creating geometry
[20:27:32][INFO] Processing gerber files (may take a while for larger boards)
[20:27:36][INFO] Adding copper from gerber files
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
[20:27:38][INFO] Adding metal mesh for F_Cu
[20:27:38][INFO] Adding metal mesh for In1_Cu
[20:27:38][INFO] Adding metal mesh for In2_Cu
[20:27:38][INFO] Adding metal mesh for B_Cu
[20:27:38][INFO] Parsing gerber file: /home/user-name/gerber2ems/examples/differential/fab/si-simulation-test-board-Edge_Cuts.gbr
[20:27:38][INFO] Adding ports grid
[20:27:38][INFO] Compiling grid
[20:27:38][INFO] Parsing gerber file: /home/user-name/gerber2ems/examples/differential/fab/si-simulation-test-board-B_Cu.gbr
[20:27:38][INFO] Parsing gerber file: /home/user-name/gerber2ems/examples/differential/fab/si-simulation-test-board-In2_Cu.gbr
[20:27:38][INFO] Parsing gerber file: /home/user-name/gerber2ems/examples/differential/fab/si-simulation-test-board-F_Cu.gbr
[20:27:38][INFO] Parsing gerber file: /home/user-name/gerber2ems/examples/differential/fab/si-simulation-test-board-In1_Cu.gbr
[20:27:38][INFO] ### Grid Generator: get nets of interest ###
[20:27:38][WARN] File with nets under test not found! (/home/user-name/gerber2ems/examples/differential/netinfo.json)
[20:27:38][INFO] ### Grid Generator: parse gerber files ###
[20:27:38][INFO] ### Grid Generator: generate X axis ###
[20:27:38][INFO] ### Grid Generator: generate Y axis ###
/home/user-name/.local/share/pipx/venvs/gerber2ems/lib/python3.12/site-packages/gerber2ems/grid_gen.py:304: RuntimeWarning: The iteration is not making good progress, as measured by the
improvement from the last ten iterations.
q1 = fsolve(series_sum2, self.cell_ratio)[0]
[20:27:38][INFO] ### Grid Generator: generate Z axis ###
[20:27:38][INFO] Grid line count, x: 269, y: 129 z: 29. Total number of cells: ~1.01M
[20:27:38][INFO] Minimal cell size, x: 50.000000, y: 30.300000 z: 30.000000 [um]
[20:27:38][INFO] Max cell size ratio, x: 4.000000, y: 1.650165 z: 2.149068
[20:27:38][INFO] Adding substrates
[20:27:38][INFO] Adding MUR boundary condition
[20:27:38][INFO] Adding vias from excellon file
[20:27:38][INFO] Adding ports
[20:27:38][INFO] Saving geometry to /home/user-name/gerber2ems/examples/differential/ems/geometry/geometry.xml
[20:27:38][INFO] Running simulation
[20:27:38][INFO] Simulating with excitation on port #0
[20:27:38][INFO] Loading geometry from /home/user-name/gerber2ems/examples/differential/ems/geometry/geometry.xml
[20:27:38][INFO] Setting up ports
[20:27:38][INFO] Starting simulation
----------------------------------------------------------------------
| openEMS 64bit -- version v0.0.36-88-g332ca7d
| (C) 2010-2023 Thorsten Liebig <[email protected]> GPL license
----------------------------------------------------------------------
Used external libraries:
CSXCAD -- Version: v0.6.3-45-g7cf8533
hdf5 -- Version: 1.10.10
compiled against: HDF5 library version: 1.10.10
tinyxml -- compiled against: 2.6.2
fparser
boost -- compiled against: 1_83
vtk -- Version: 9.1.0
compiled against: 9.1.0
Create FDTD operator (compressed SSE + multi-threading)
FDTD simulation size: 269x129x29 --> 1.00633e+06 FDTD cells
FDTD timestep is: 6.40353e-14 s; Nyquist rate: 1301 timesteps @6.00168e+09 Hz
openEMS::SetupFDTD: Warning, the timestep seems to be very small --> long simulation. Check your mesh!?
Excitation signal length is: 15427 timesteps (9.87873e-10s)
Max. number of timesteps: 57395 ( --> 3.72043 * Excitation signal length)
Create FDTD engine (compressed SSE + multi-threading)
Warning: No primitives found in property: Plane!
Warning: Unused primitive (type: Polygon) detected in property: Gerber_0!
Warning: Unused primitive (type: Polygon) detected in property: Gerber_0!
Warning: Unused primitive (type: Polygon) detected in property: Gerber_0!
Warning: Unused primitive (type: Polygon) detected in property: Gerber_0!
Warning: Unused primitive (type: Polygon) detected in property: Gerber_0!
Warning: Unused primitive (type: Polygon) detected in property: Gerber_0!
Warning: Unused primitive (type: Polygon) detected in property: Gerber_0!
Warning: Unused primitive (type: Polygon) detected in property: Gerber_0!
Warning: Unused primitive (type: Polygon) detected in property: Gerber_0!
Warning: Unused primitive (type: Polygon) detected in property: Gerber_0!
.....
Multithreaded Engine: Best performance found using 4 threads.
[@ 30s] Timestep: 4875 || Speed: 182.4 MC/s (5.516e-03 s/TS) || Energy: ~2.93e-16 (- 0.00dB)
[@ 35s] Timestep: 5850 || Speed: 185.5 MC/s (5.425e-03 s/TS) || Energy: ~2.42e-15 (- 0.00dB)
[@ 41s] Timestep: 6825 || Speed: 185.3 MC/s (5.430e-03 s/TS) || Energy: ~2.26e-15 (- 0.31dB)
[@ 45s] Timestep: 7713 || Speed: 185.4 MC/s (5.429e-03 s/TS) || Energy: ~9.63e-15 (- 0.00dB)
[@ 49s] Timestep: 8450 || Speed: 184.5 MC/s (5.455e-03 s/TS) || Energy: ~1.57e-14 (- 0.00dB)
[@ 54s] Timestep: 9100 || Speed: 143.7 MC/s (7.004e-03 s/TS) || Energy: ~1.26e-14 (- 0.95dB)
[@ 59s] Timestep: 9750 || Speed: 136.0 MC/s (7.401e-03 s/TS) || Energy: ~1.08e-14 (- 1.62dB)
[@ 1m03s] Timestep: 10400 || Speed: 149.7 MC/s (6.724e-03 s/TS) || Energy: ~1.15e-14 (- 1.33dB)
[@ 1m07s] Timestep: 11050 || Speed: 157.0 MC/s (6.409e-03 s/TS) || Energy: ~1.18e-14 (- 1.25dB)
[@ 1m12s] Timestep: 11700 || Speed: 155.8 MC/s (6.460e-03 s/TS) || Energy: ~1.23e-14 (- 1.06dB)
[@ 1m16s] Timestep: 12350 || Speed: 160.4 MC/s (6.272e-03 s/TS) || Energy: ~1.14e-14 (- 1.37dB)
[@ 1m21s] Timestep: 13325 || Speed: 173.2 MC/s (5.810e-03 s/TS) || Energy: ~9.15e-15 (- 2.34dB)
[@ 1m25s] Timestep: 13975 || Speed: 154.9 MC/s (6.497e-03 s/TS) || Energy: ~4.38e-15 (- 5.54dB)
[@ 1m30s] Timestep: 14625 || Speed: 152.6 MC/s (6.593e-03 s/TS) || Energy: ~2.02e-15 (- 8.90dB)
[@ 1m34s] Timestep: 15275 || Speed: 141.3 MC/s (7.121e-03 s/TS) || Energy: ~2.46e-15 (- 8.04dB)
[@ 1m39s] Timestep: 15925 || Speed: 159.3 MC/s (6.318e-03 s/TS) || Energy: ~2.03e-15 (- 8.88dB)
[@ 1m43s] Timestep: 16575 || Speed: 155.9 MC/s (6.457e-03 s/TS) || Energy: ~1.41e-15 (-10.47dB)
[@ 1m47s] Timestep: 17225 || Speed: 159.6 MC/s (6.305e-03 s/TS) || Energy: ~1.21e-15 (-11.13dB)
[@ 1m51s] Timestep: 17875 || Speed: 158.7 MC/s (6.342e-03 s/TS) || Energy: ~1.03e-15 (-11.82dB)
[@ 1m57s] Timestep: 18850 || Speed: 172.1 MC/s (5.849e-03 s/TS) || Energy: ~7.88e-16 (-12.99dB)
[@ 2m02s] Timestep: 19825 || Speed: 173.4 MC/s (5.804e-03 s/TS) || Energy: ~4.52e-16 (-15.41dB)
[@ 2m08s] Timestep: 20800 || Speed: 168.9 MC/s (5.957e-03 s/TS) || Energy: ~2.24e-16 (-18.45dB)
[@ 2m12s] Timestep: 21450 || Speed: 159.5 MC/s (6.310e-03 s/TS) || Energy: ~2.15e-16 (-18.64dB)
[@ 2m17s] Timestep: 22100 || Speed: 151.6 MC/s (6.638e-03 s/TS) || Energy: ~1.91e-16 (-19.15dB)
[@ 2m21s] Timestep: 22750 || Speed: 161.3 MC/s (6.238e-03 s/TS) || Energy: ~1.67e-16 (-19.73dB)
[@ 2m27s] Timestep: 23725 || Speed: 164.3 MC/s (6.124e-03 s/TS) || Energy: ~1.01e-16 (-21.90dB)
[@ 2m32s] Timestep: 24700 || Speed: 171.5 MC/s (5.869e-03 s/TS) || Energy: ~7.39e-17 (-23.27dB)
[@ 2m38s] Timestep: 25675 || Speed: 182.1 MC/s (5.527e-03 s/TS) || Energy: ~4.61e-17 (-25.32dB)
[@ 2m43s] Timestep: 26650 || Speed: 182.5 MC/s (5.514e-03 s/TS) || Energy: ~3.45e-17 (-26.57dB)
[@ 2m48s] Timestep: 27625 || Speed: 184.4 MC/s (5.458e-03 s/TS) || Energy: ~2.28e-17 (-28.37dB)
[@ 2m54s] Timestep: 28600 || Speed: 182.5 MC/s (5.514e-03 s/TS) || Energy: ~2.46e-17 (-28.04dB)
[@ 2m59s] Timestep: 29575 || Speed: 179.0 MC/s (5.623e-03 s/TS) || Energy: ~9.80e-18 (-32.04dB)
[@ 3m05s] Timestep: 30550 || Speed: 179.2 MC/s (5.616e-03 s/TS) || Energy: ~9.50e-18 (-32.17dB)
[@ 3m10s] Timestep: 31525 || Speed: 178.8 MC/s (5.629e-03 s/TS) || Energy: ~6.13e-18 (-34.08dB)
[@ 3m16s] Timestep: 32500 || Speed: 180.5 MC/s (5.576e-03 s/TS) || Energy: ~5.12e-18 (-34.86dB)
[@ 3m21s] Timestep: 33475 || Speed: 181.7 MC/s (5.539e-03 s/TS) || Energy: ~2.91e-18 (-37.32dB)
[@ 3m26s] Timestep: 34450 || Speed: 183.8 MC/s (5.475e-03 s/TS) || Energy: ~3.38e-18 (-36.67dB)
[@ 3m33s] Timestep: 35425 || Speed: 152.3 MC/s (6.610e-03 s/TS) || Energy: ~1.21e-18 (-41.13dB)
[@ 3m38s] Timestep: 36075 || Speed: 115.1 MC/s (8.744e-03 s/TS) || Energy: ~1.59e-18 (-39.94dB)
[@ 3m44s] Timestep: 36725 || Speed: 119.7 MC/s (8.410e-03 s/TS) || Energy: ~1.08e-18 (-41.63dB)
[@ 3m50s] Timestep: 37375 || Speed: 117.4 MC/s (8.572e-03 s/TS) || Energy: ~1.15e-18 (-41.36dB)
[@ 3m55s] Timestep: 38025 || Speed: 115.9 MC/s (8.683e-03 s/TS) || Energy: ~6.62e-19 (-43.75dB)
[@ 4m00s] Timestep: 38675 || Speed: 123.2 MC/s (8.166e-03 s/TS) || Energy: ~9.95e-19 (-41.98dB)
[@ 4m06s] Timestep: 39325 || Speed: 115.6 MC/s (8.704e-03 s/TS) || Energy: ~4.72e-19 (-45.22dB)
[@ 4m12s] Timestep: 39975 || Speed: 118.6 MC/s (8.483e-03 s/TS) || Energy: ~5.38e-19 (-44.65dB)
[@ 4m17s] Timestep: 40625 || Speed: 122.6 MC/s (8.211e-03 s/TS) || Energy: ~4.26e-19 (-45.66dB)
[@ 4m22s] Timestep: 41275 || Speed: 118.7 MC/s (8.475e-03 s/TS) || Energy: ~3.68e-19 (-46.29dB)
[@ 4m28s] Timestep: 41925 || Speed: 122.3 MC/s (8.228e-03 s/TS) || Energy: ~2.87e-19 (-47.37dB)
[@ 4m33s] Timestep: 42575 || Speed: 131.3 MC/s (7.663e-03 s/TS) || Energy: ~3.10e-19 (-47.04dB)
[@ 4m38s] Timestep: 43550 || Speed: 182.7 MC/s (5.508e-03 s/TS) || Energy: ~3.23e-19 (-46.86dB)
[@ 4m44s] Timestep: 44525 || Speed: 180.9 MC/s (5.562e-03 s/TS) || Energy: ~2.37e-19 (-48.21dB)
[@ 4m49s] Timestep: 45500 || Speed: 184.1 MC/s (5.466e-03 s/TS) || Energy: ~1.11e-19 (-51.52dB)
[@ 4m55s] Timestep: 46475 || Speed: 150.7 MC/s (6.677e-03 s/TS) || Energy: ~1.14e-19 (-51.40dB)
[@ 5m01s] Timestep: 47450 || Speed: 179.9 MC/s (5.595e-03 s/TS) || Energy: ~1.54e-19 (-50.09dB)
[@ 5m06s] Timestep: 48425 || Speed: 179.9 MC/s (5.593e-03 s/TS) || Energy: ~2.15e-19 (-48.63dB)
[@ 5m12s] Timestep: 49400 || Speed: 183.8 MC/s (5.476e-03 s/TS) || Energy: ~1.91e-19 (-49.14dB)
[@ 5m17s] Timestep: 50375 || Speed: 182.4 MC/s (5.517e-03 s/TS) || Energy: ~8.28e-20 (-52.77dB)
[@ 5m23s] Timestep: 51350 || Speed: 177.8 MC/s (5.658e-03 s/TS) || Energy: ~3.37e-20 (-56.68dB)
[@ 5m27s] Timestep: 52000 || Speed: 147.0 MC/s (6.846e-03 s/TS) || Energy: ~2.12e-19 (-48.69dB)
[@ 5m32s] Timestep: 52650 || Speed: 135.9 MC/s (7.406e-03 s/TS) || Energy: ~4.33e-20 (-55.59dB)
[@ 5m37s] Timestep: 53300 || Speed: 137.0 MC/s (7.345e-03 s/TS) || Energy: ~1.90e-19 (-49.16dB)
[@ 5m41s] Timestep: 53950 || Speed: 139.1 MC/s (7.234e-03 s/TS) || Energy: ~6.55e-20 (-53.79dB)
[@ 5m46s] Timestep: 54600 || Speed: 141.2 MC/s (7.128e-03 s/TS) || Energy: ~1.55e-19 (-50.05dB)
[@ 5m51s] Timestep: 55250 || Speed: 140.7 MC/s (7.154e-03 s/TS) || Energy: ~9.23e-20 (-52.30dB)
[@ 5m55s] Timestep: 55900 || Speed: 138.7 MC/s (7.257e-03 s/TS) || Energy: ~1.23e-19 (-51.07dB)
[@ 6m00s] Timestep: 56550 || Speed: 141.5 MC/s (7.111e-03 s/TS) || Energy: ~1.25e-19 (-51.00dB)
[@ 6m05s] Timestep: 57200 || Speed: 138.8 MC/s (7.248e-03 s/TS) || Energy: ~8.25e-20 (-52.79dB)
RunFDTD: Warning: Max. number of timesteps was reached before the end-criteria of -60dB was reached...
You may want to choose a higher number of max. timesteps...
Time for 57395 iterations with 1006329.00 cells : 366.48 sec
Speed: 157.60 MCells/s
[20:34:46][INFO] Simulating with excitation on port #2
[20:34:46][INFO] Loading geometry from /home/user-name/gerber2ems/examples/differential/ems/geometry/geometry.xml
[20:34:46][INFO] Setting up ports
[20:34:46][INFO] Starting simulation```