add a TerminalSpec for RF specific mode information

adding support for colocated fields

fixing bug for more complicated shapes

adding tests, fixing symmetric conditions, fixing for 2D structures

fix simulation validator for terminal spec

refactor by splitting the path integral specification away from the integral computation, now the path specification handles pretty much everything, except for the final integral computation and results preparation

rename auto patch spec to generator type name, fixed tests

add test for sim validation and improved doc strings

fix regression

fix python 3.9 tests

reorg of ModeData, the impedance is now calculated by the ModeSolver class avoiding the need for a duplicate terminal spec

add more descriptive warnings to composite current integral

Author: dmarek-flex

tests/test_components/test_microwave.py

@@ -3648,3 +3648,54 @@ def test_create_sim_multiphysics_with_incompatibilities():
                 ),
             ],
         )
+
+
+def test_validate_terminal_spec_generation():
+    """Test that auto generation of path specs is correctly validated for currently unsupported structures."""
+    freq0 = 10e9
+    mm = 1e3
+    run_time_spec = td.RunTimeSpec(quality_factor=3.0)
+    size = (10 * mm, 10 * mm, 10 * mm)
+    size_mon = (0, 8 * mm, 8 * mm)
+
+    # Currently limited to generation of axis aligned boxes around conductors,
+    # so the path may intersect other nearby conductors, like in this coaxial cable
+    coaxial = td.Structure(
+        geometry=td.GeometryGroup(
+            geometries=(
+                td.ClipOperation(
+                    operation="difference",
+                    geometry_a=td.Cylinder(
+                        axis=0, radius=2.5 * mm, center=(0, 0, 0), length=td.inf
+                    ),
+                    geometry_b=td.Cylinder(
+                        axis=0, radius=1.3 * mm, center=(0, 0, 0), length=td.inf
+                    ),
+                ),
+                td.Cylinder(axis=0, radius=1 * mm, center=(0, 0, 0), length=td.inf),
+            )
+        ),
+        medium=td.PEC,
+    )
+    mode_spec = td.ModeSpec(num_modes=2, target_neff=1.8, terminal_spec=td.TerminalSpec())
+
+    mode_mon = td.ModeMonitor(
+        center=(0, 0, 0),
+        size=size_mon,
+        freqs=[freq0],
+        name="mode_1",
+        colocate=False,
+        mode_spec=mode_spec,
+    )
+    sim = td.Simulation(
+        run_time=run_time_spec,
+        size=size,
+        sources=[],
+        structures=[coaxial],
+        grid_spec=td.GridSpec.uniform(dl=0.1 * mm),
+        monitors=[mode_mon],
+    )
+
+    # check that validation error is caught
+    with pytest.raises(SetupError):
+        sim._validate_terminal_specs()

tests/test_components/test_simulation.py

@@ -315,6 +315,16 @@ def test_abs():
     _ = data.abs
 
 
+def test_angle():
+    # Make sure works on real data and the type is correct
+    data = make_scalar_field_time_data_array("Ex")
+    angle_data = data.angle
+    assert type(data) is type(angle_data)
+    data = make_mode_amps_data_array()
+    angle_data = data.angle
+    assert type(data) is type(angle_data)
+
+
 def test_heat_data_array():
     T = [0, 1e-12, 2e-12]
     _ = td.HeatDataArray((1 + 1j) * np.random.random((3,)), coords={"T": T})

tests/test_data/test_data_arrays.py

@@ -14,10 +14,18 @@
 import tidy3d as td
 import tidy3d.plugins.microwave as mw
 from tidy3d import FieldData
+from tidy3d.components.data.data_array import FreqModeDataArray
 from tidy3d.constants import ETA_0
 from tidy3d.exceptions import DataError
 
-from ..utils import get_spatial_coords_dict, run_emulated
+from ..utils import AssertLogLevel, get_spatial_coords_dict, run_emulated
+
+MAKE_PLOTS = False
+if MAKE_PLOTS:
+    # Interative plotting for debugging
+    from matplotlib import use
+
+    use("TkAgg")
 
 # Using similar code as "test_data/test_data_arrays.py"
 MON_SIZE = (2, 1, 0)
@@ -527,6 +535,41 @@ def test_custom_current_integral_normal_y():
     current_integral.compute_current(SIM_Z_DATA["field"])
 
 
+def test_composite_current_integral_warnings():
+    """Ensures that the checks function correctly on some test data."""
+    f = [2e9, 3e9, 4e9]
+    mode_index = list(np.arange(5))
+    coords = {"f": f, "mode_index": mode_index}
+    values = np.ones((3, 5))
+
+    path_spec = td.CurrentIntegralAxisAlignedSpec(center=(0, 0, 0), size=(2, 2, 0), sign="+")
+    composite_integral = mw.CompositeCurrentIntegral(
+        center=(0, 0, 0), size=(4, 4, 0), path_specs=[path_spec], sum_spec="split"
+    )
+
+    phase_diff = FreqModeDataArray(np.angle(values), coords=coords)
+    with AssertLogLevel(None):
+        assert composite_integral._check_phase_sign_consistency(phase_diff)
+
+    values[1, 2:] = -1
+    phase_diff = FreqModeDataArray(np.angle(values), coords=coords)
+    with AssertLogLevel("WARNING"):
+        assert not composite_integral._check_phase_sign_consistency(phase_diff)
+
+    values = np.ones((3, 5))
+    in_phase = FreqModeDataArray(values, coords=coords)
+    values = 0.5 * np.ones((3, 5))
+    out_phase = FreqModeDataArray(values, coords=coords)
+    with AssertLogLevel(None):
+        assert composite_integral._check_phase_amplitude_consistency(in_phase, out_phase)
+
+    values = 0.5 * np.ones((3, 5))
+    values[2, 4:] = 1.5
+    out_phase = FreqModeDataArray(values, coords=coords)
+    with AssertLogLevel("WARNING"):
+        assert not composite_integral._check_phase_amplitude_consistency(in_phase, out_phase)
+
+
 def test_custom_path_integral_accuracy():
     """Test the accuracy of the custom path integral."""
     field_data = make_coax_field_data()
@@ -785,13 +828,11 @@ def test_lobe_measurements(apply_cyclic_extension, include_endpoint):
 @pytest.mark.parametrize("min_value", [0.0, 1.0])
 def test_lobe_plots(min_value):
     """Run the lobe measurer on some test data and plot the results."""
-    # Interative plotting for debugging
-    # from matplotlib import use
-    # use("TkAgg")
     theta = np.linspace(0, 2 * np.pi, 301)
     Urad = np.cos(theta) ** 2 * np.cos(3 * theta) ** 2 + min_value
     lobe_measurer = mw.LobeMeasurer(angle=theta, radiation_pattern=Urad)
     _, ax = plt.subplots(1, 1, subplot_kw={"projection": "polar"})
     ax.plot(theta, Urad, "k")
     lobe_measurer.plot(0, ax)
-    plt.show()
+    if MAKE_PLOTS:
+        plt.show()

tests/test_plugins/test_microwave.py

@@ -17,6 +17,16 @@
 from tidy3d.components.microwave.data.monitor_data import (
     AntennaMetricsData,
 )
+from tidy3d.components.microwave.path_spec import (
+    CompositeCurrentIntegralSpec,
+    CurrentIntegralAxisAlignedSpec,
+    CustomCurrentIntegral2DSpec,
+    CustomVoltageIntegral2DSpec,
+    VoltageIntegralAxisAlignedSpec,
+)
+from tidy3d.components.microwave.terminal_spec import (
+    TerminalSpec,
+)
 from tidy3d.components.spice.analysis.dc import (
     ChargeToleranceSpec,
     IsothermalSteadyChargeDCAnalysis,
@@ -439,6 +449,7 @@ def set_logging_level(level: str) -> None:
     "ChargeToleranceSpec",
     "ClipOperation",
     "CoaxialLumpedResistor",
+    "CompositeCurrentIntegralSpec",
     "ConstantDoping",
     "ConstantMobilityModel",
     "ContinuousWave",
@@ -449,8 +460,10 @@ def set_logging_level(level: str) -> None:
     "Coords1D",
     "CornerFinderSpec",
     "CurrentBC",
+    "CurrentIntegralAxisAlignedSpec",
     "CustomAnisotropicMedium",
     "CustomChargePerturbation",
+    "CustomCurrentIntegral2DSpec",
     "CustomCurrentSource",
     "CustomDebye",
     "CustomDrude",
@@ -463,6 +476,7 @@ def set_logging_level(level: str) -> None:
     "CustomPoleResidue",
     "CustomSellmeier",
     "CustomSourceTime",
+    "CustomVoltageIntegral2DSpec",
     "Cylinder",
     "DCCurrentSource",
     "DCVoltageSource",
@@ -668,6 +682,7 @@ def set_logging_level(level: str) -> None:
     "TemperatureBC",
     "TemperatureData",
     "TemperatureMonitor",
+    "TerminalSpec",
     "TetrahedralGridDataset",
     "Transformed",
     "TriangleMesh",
@@ -682,6 +697,7 @@ def set_logging_level(level: str) -> None:
     "Updater",
     "VisualizationSpec",
     "VoltageBC",
+    "VoltageIntegralAxisAlignedSpec",
     "VoltageSourceType",
     "VolumetricAveraging",
     "YeeGrid",

tidy3d/__init__.py

@@ -205,6 +205,13 @@ def abs(self):
         """Absolute value of data array."""
         return abs(self)
 
+    @property
+    def angle(self):
+        """Angle or phase value of data array."""
+        values = np.angle(self.values)
+        SelfType = type(self)
+        return SelfType(values, coords=self.coords)
+
     @property
     def is_uniform(self):
         """Whether each element is of equal value in the data array"""

tidy3d/components/data/data_array.py

@@ -1602,11 +1602,19 @@ class ModeData(ModeSolverDataset, ElectromagneticFieldData):
 
     eps_spec: list[EpsSpecType] = pd.Field(
         None,
-        title="Permettivity Specification",
+        title="Permittivity Specification",
         description="Characterization of the permittivity profile on the plane where modes are "
         "computed. Possible values are 'diagonal', 'tensorial_real', 'tensorial_complex'.",
     )
 
+    Z0: Optional[FreqModeDataArray] = pd.Field(
+        None,
+        title="Characteristic Impedance",
+        description="Optional quantity calculated for transmission lines."
+        "The characteristic impedance is only calculated when a :class:``TerminalSpec`` "
+        "is provided to the :class:``ModeSpec`` associated with this data.",
+    )
+
     @pd.validator("eps_spec", always=True)
     @skip_if_fields_missing(["monitor"])
     def eps_spec_match_mode_spec(cls, val, values):
@@ -2055,6 +2063,10 @@ def modes_info(self) -> xr.Dataset:
             info["wg TE fraction"] = self.pol_fraction_waveguide["te"]
             info["wg TM fraction"] = self.pol_fraction_waveguide["tm"]
 
+        if self.Z0 is not None:
+            info["Re(Z0)"] = self.Z0.real
+            info["Im(Z0)"] = self.Z0.imag
+
         return xr.Dataset(data_vars=info)
 
     def to_dataframe(self) -> DataFrame: