adding support for coaxial lumped ports and elements

extending impedance calculator for custom paths and fixing one bug

modified convention for vertices in custom path integral

Author: dmarek-flex

CHANGELOG.md

@@ -28,6 +28,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Support for complex and self-intersecting polyslabs in adjoint module via `JaxComplexPolySlab`.
 - Support for `.gz` files in `Simulation` version updater.
 - Warning if a nonuniform custom medium is intersecting `PlaneWave`, `GaussianBeam`, `AstigmaticGaussianBeam`, `FieldProjectionCartesianMonitor`, `FieldProjectionAngleMonitor`, `FieldProjectionKSpaceMonitor`, and `DiffractionMonitor`.
+- Added a `CoaxialLumpedPort` and `CoaxialLumpedResistor` for coaxial type transmission lines and excitations.
 
 ### Changed
 - `tidy3d convert` from `.lsf` files to tidy3d scripts has moved to another repository at `https://github.com/hirako22/Lumerical-to-Tidy3D-Converter`.

docs/api/lumped_elements.rst

@@ -10,3 +10,4 @@ Passive elements
    :template: module.rst
 
    tidy3d.LumpedResistor
+   tidy3d.CoaxialLumpedResistor

docs/api/plugins/microwave.rst

@@ -10,4 +10,7 @@ Microwave
    tidy3d.plugins.microwave.AxisAlignedPathIntegral 
    tidy3d.plugins.microwave.VoltageIntegralAxisAligned
    tidy3d.plugins.microwave.CurrentIntegralAxisAligned
+   tidy3d.plugins.microwave.CustomPathIntegral2D 
+   tidy3d.plugins.microwave.CustomVoltageIntegral2D
+   tidy3d.plugins.microwave.CustomCurrentIntegral2D
    tidy3d.plugins.microwave.ImpedanceCalculator

docs/api/plugins/smatrix.rst

@@ -12,4 +12,5 @@ Scattering Matrix Calculator
    tidy3d.plugins.smatrix.ModalPortDataArray
    tidy3d.plugins.smatrix.TerminalComponentModeler
    tidy3d.plugins.smatrix.LumpedPort
-   tidy3d.plugins.smatrix.LumpedPortDataArray
+   tidy3d.plugins.smatrix.LumpedPortDataArray
+   tidy3d.plugins.smatrix.CoaxialLumpedPort

docs/notebooks

@@ -754,10 +754,16 @@ def test_lumped_resistor():
         voltage_axis=0,
         name="R",
     )
-    _ = resistor.sheet_conductance
+    _ = resistor._sheet_conductance
     normal_axis = resistor.normal_axis
     assert normal_axis == 1
 
+    # Check conversion to geometry
+    _ = resistor.to_structure
+
+    # Check conversion to mesh overrides
+    _ = resistor.to_mesh_overrides()
+
     # error if voltage axis is not in plane with the resistor
     with pytest.raises(pydantic.ValidationError):
         _ = td.LumpedResistor(
@@ -785,3 +791,45 @@ def test_lumped_resistor():
             voltage_axis=2,
             name="R",
         )
+
+
+def test_coaxial_lumped_resistor():
+    resistor = td.CoaxialLumpedResistor(
+        resistance=50.0,
+        center=[0, 0, 0],
+        outer_diameter=3,
+        inner_diameter=1,
+        normal_axis=1,
+        name="R",
+    )
+
+    _ = resistor._sheet_conductance
+    normal_axis = resistor.normal_axis
+    assert normal_axis == 1
+
+    # Check conversion to geometry
+    _ = resistor.to_structure
+
+    # Check conversion to mesh overrides
+    _ = resistor.to_mesh_overrides()
+
+    # error if inner diameter is larger
+    with pytest.raises(pydantic.ValidationError):
+        _ = td.CoaxialLumpedResistor(
+            resistance=50.0,
+            center=[0, 0, 0],
+            outer_diameter=3,
+            inner_diameter=4,
+            normal_axis=1,
+            name="R",
+        )
+
+    with pytest.raises(pydantic.ValidationError):
+        _ = td.CoaxialLumpedResistor(
+            resistance=50.0,
+            center=[0, 0, np.inf],
+            outer_diameter=3,
+            inner_diameter=1,
+            normal_axis=1,
+            name="R",
+        )

tests/test_components/test_medium.py

@@ -691,6 +691,15 @@ def test_plot_boundaries():
     plt.close()
 
 
+def test_plot_with_lumped_elements():
+    load = td.LumpedResistor(
+        center=(0, 0, 0), size=(1, 2, 0), name="resistor", voltage_axis=0, resistance=50
+    )
+    sim_test = SIM_FULL.updated_copy(lumped_elements=[load])
+    sim_test.plot(z=0)
+    plt.close()
+
+
 def test_wvl_mat_grid():
     td.Simulation.wvl_mat_min.fget(SIM_FULL)
 
@@ -2398,7 +2407,6 @@ def test_to_gds(tmp_path):
 def test_sim_subsection(unstructured, nz):
     region = td.Box(size=(0.3, 0.5, 0.7), center=(0.1, 0.05, 0.02))
     region_xy = td.Box(size=(0.3, 0.5, 0), center=(0.1, 0.05, 0.02))
-    _ = td.Box(size=(0, 0.5, 0.7), center=(0.1, 0.05, 0.02))
 
     sim_red = SIM_FULL.subsection(region=region)
     assert sim_red.structures != SIM_FULL.structures
@@ -2809,19 +2817,38 @@ def test_suggested_mesh_overrides():
         lumped_elements=[resistor],
     )
 
-    suggested_mesh_overrides = sim.suggest_mesh_overrides()
-    assert len(suggested_mesh_overrides) == 2
-    grid_spec = sim.grid_spec.copy(
-        update={
-            "override_structures": list(sim.grid_spec.override_structures)
-            + suggested_mesh_overrides,
-        }
+    def update_sim_with_suggested_overrides(sim):
+        suggested_mesh_overrides = sim.suggest_mesh_overrides()
+        assert len(suggested_mesh_overrides) == 2
+        grid_spec = sim.grid_spec.copy(
+            update={
+                "override_structures": list(sim.grid_spec.override_structures)
+                + suggested_mesh_overrides,
+            }
+        )
+
+        return sim.updated_copy(
+            grid_spec=grid_spec,
+        )
+
+    _ = update_sim_with_suggested_overrides(sim)
+
+    coax_resistor = td.CoaxialLumpedResistor(
+        resistance=50.0,
+        center=[0, 0, 0],
+        outer_diameter=2,
+        inner_diameter=0.5,
+        normal_axis=0,
+        name="R",
     )
 
-    _ = sim.updated_copy(
-        grid_spec=grid_spec,
+    sim = sim.updated_copy(
+        lumped_elements=[coax_resistor],
+        grid_spec=td.GridSpec.uniform(dl=0.1),
     )
 
+    _ = update_sim_with_suggested_overrides(sim)
+
 
 def test_run_time_spec():
     run_time_spec = td.RunTimeSpec(quality_factor=3.0)

tests/test_components/test_simulation.py

@@ -3,6 +3,7 @@
 import tidy3d as td
 from tidy3d.plugins.smatrix import (
     LumpedPort,
+    CoaxialLumpedPort,
     TerminalComponentModeler,
 )
 
@@ -24,6 +25,10 @@
 freq_start = 1e8
 freq_stop = 10e9
 
+# Coaxial dimensions
+Rinner = 0.2768 * 1e-3
+Router = 1.0 * 1e-3
+
 
 def make_simulation(planar_pec: bool, length: float = None, auto_grid: bool = True):
     if length:
@@ -156,3 +161,124 @@ def make_component_modeler(
     )
 
     return modeler
+
+
+def make_coaxial_simulation(length: float = None, auto_grid: bool = True):
+    if length:
+        coax_length = length
+    else:
+        coax_length = default_strip_length
+
+    # wavelength / frequency
+    freq0 = (freq_start + freq_stop) / 2
+    fwidth = freq_stop - freq_start
+    wavelength0 = td.C_0 / freq0
+    run_time = 60 / fwidth
+
+    # Spatial grid specification
+    if auto_grid:
+        grid_spec = td.GridSpec.auto(min_steps_per_wvl=10, wavelength=td.C_0 / freq_stop)
+    else:
+        grid_spec = td.GridSpec.uniform(wavelength0 / 11)
+
+    # Make structures
+    inner_conductor = td.Cylinder(
+        center=(0, 0, 0),
+        radius=Rinner,
+        length=length,
+        axis=2,
+    )
+
+    outer_1 = td.Cylinder(
+        center=(0, 0, 0),
+        radius=Router,
+        length=length,
+        axis=2,
+    )
+
+    outer_2 = td.Cylinder(
+        center=(0, 0, 0),
+        radius=Router * 1.1,
+        length=length,
+        axis=2,
+    )
+
+    outer_shell_clip = td.ClipOperation(
+        operation="difference", geometry_a=outer_2, geometry_b=outer_1
+    )
+
+    inner = td.Structure(
+        geometry=inner_conductor,
+        medium=pec,
+    )
+
+    outer_shell = td.Structure(
+        geometry=outer_shell_clip,
+        medium=pec,
+    )
+
+    structures_list = [inner, outer_shell]
+
+    # Make simulation
+    center_sim = [0, 0, 0]
+    size_sim = [
+        2 * Router,
+        2 * Router,
+        coax_length + 0.5 * wavelength0,
+    ]
+
+    sim = td.Simulation(
+        center=center_sim,
+        size=size_sim,
+        grid_spec=grid_spec,
+        structures=structures_list,
+        sources=[],
+        monitors=[],
+        run_time=run_time,
+        boundary_spec=td.BoundarySpec.all_sides(boundary=td.PML()),
+        shutoff=1e-4,
+    )
+
+    return sim
+
+
+def make_coaxial_component_modeler(
+    reference_impedance: complex = 50,
+    length: float = None,
+    port_refinement: bool = True,
+    auto_grid: bool = True,
+    **kwargs,
+):
+    if length:
+        coax_length = length
+    else:
+        coax_length = default_strip_length
+
+    sim = make_coaxial_simulation(length=coax_length, auto_grid=auto_grid)
+
+    center_src1 = [0, 0, -coax_length / 2]
+
+    port_cells = None
+    if port_refinement:
+        port_cells = 21
+
+    port_1 = CoaxialLumpedPort(
+        center=center_src1,
+        outer_diameter=2 * Router,
+        inner_diameter=2 * Rinner,
+        normal_axis=2,
+        direction="+",
+        name="coax_port_1",
+        num_grid_cells=port_cells,
+        impedance=reference_impedance,
+    )
+    center_src2 = [0, 0, coax_length / 2]
+    port_2 = port_1.updated_copy(name="coax_port_2", center=center_src2, direction="-")
+    ports = [port_1, port_2]
+    freqs = np.linspace(freq_start, freq_stop, 100)
+
+    modeler = TerminalComponentModeler(
+        simulation=sim, ports=ports, freqs=freqs, remove_dc_component=False, verbose=True, **kwargs
+    )
+
+    return modeler

tests/test_plugins/terminal_component_modeler_def.py

@@ -13,6 +13,8 @@
 from tidy3d.plugins.microwave import (
     VoltageIntegralAxisAligned,
     CurrentIntegralAxisAligned,
+    CustomVoltageIntegral2D,
+    CustomCurrentIntegral2D,
     ImpedanceCalculator,
 )
 
@@ -379,3 +381,60 @@ def test_coupled_microstrip_model():
     assert np.isclose(Z_odd, 39, rtol=0.01)
     assert np.isclose(eps_even, 3.42, rtol=0.01)
     assert np.isclose(eps_odd, 2.80, rtol=0.01)
+
+
+def test_frequency_monitor_custom_voltage_integral():
+    length = 0.5
+    size = [0, 0, 0]
+    size[1] = length
+    # Make line
+    vertices = [(0, 0), (0, 0.2), (0, 0.4)]
+    voltage_integral = CustomVoltageIntegral2D(axis=2, position=0, vertices=vertices)
+    voltage_integral.compute_voltage(SIM_Z_DATA["field"])
+
+
+def test_vertices_validator_custom_current_integral():
+    length = 0.5
+    size = [0, 0, 0]
+    size[1] = length
+    # Make wrong box
+    vertices = [(0.2, -0.2, 0.5), (0.2, 0.2), (-0.2, 0.2), (-0.2, -0.2), (0.2, -0.2)]
+
+    with pytest.raises(pydantic.ValidationError):
+        _ = CustomCurrentIntegral2D(axis=2, position=0, vertices=vertices)
+
+    # Make wrong box shape
+    vertices = [(0.2, 0.2, -0.2, -0.2, 0.2), (-0.2, 0.2, 0.2, -0.2, 0.2)]
+    with pytest.raises(pydantic.ValidationError):
+        _ = CustomCurrentIntegral2D(axis=2, position=0, vertices=vertices)
+
+
+def test_fields_missing_custom_current_integral():
+    length = 0.5
+    size = [0, 0, 0]
+    size[1] = length
+    # Make box
+    vertices = [(0.2, -0.2), (0.2, 0.2), (-0.2, 0.2), (-0.2, -0.2), (0.2, -0.2)]
+    current_integral = CustomCurrentIntegral2D(axis=2, position=0, vertices=vertices)
+    with pytest.raises(DataError):
+        current_integral.compute_current(SIM_Z_DATA["ExHx"])
+
+
+def test_time_monitor_custom_current_integral():
+    length = 0.5
+    size = [0, 0, 0]
+    size[1] = length
+    # Make box
+    vertices = [(0.2, -0.2), (0.2, 0.2), (-0.2, 0.2), (-0.2, -0.2), (0.2, -0.2)]
+    current_integral = CustomCurrentIntegral2D(axis=2, position=0, vertices=vertices)
+    current_integral.compute_current(SIM_Z_DATA["field_time"])
+
+
+def test_mode_solver_custom_current_integral():
+    length = 0.5
+    size = [0, 0, 0]
+    size[1] = length
+    # Make box
+    vertices = [(0.2, -0.2), (0.2, 0.2), (-0.2, 0.2), (-0.2, -0.2), (0.2, -0.2)]
+    current_integral = CustomCurrentIntegral2D(axis=2, position=0, vertices=vertices)
+    current_integral.compute_current(SIM_Z_DATA["mode"])