tidy3d.LinearLumpedElement

class LinearLumpedElement

Bases: RectangularLumpedElement

Lumped element representing a network consisting of resistors, capacitors, and inductors.

Parameters:

• attrs (dict = {}) – Dictionary storing arbitrary metadata for a Tidy3D object. This dictionary can be freely used by the user for storing data without affecting the operation of Tidy3D as it is not used internally. Note that, unlike regular Tidy3D fields, attrs are mutable. For example, the following is allowed for setting an attr obj.attrs['foo'] = bar. Also note that Tidy3D` will raise a TypeError if attrs contain objects that can not be serialized. One can check if attrs are serializable by calling obj.json().

• center (Union[tuple[Union[float, autograd.tracer.Box], Union[float, autograd.tracer.Box], Union[float, autograd.tracer.Box]], Box] = (0.0, 0.0, 0.0)) – [units = um]. Center of object in x, y, and z.

• size (Union[tuple[Union[pydantic.v1.types.NonNegativeFloat, autograd.tracer.Box], Union[pydantic.v1.types.NonNegativeFloat, autograd.tracer.Box], Union[pydantic.v1.types.NonNegativeFloat, autograd.tracer.Box]], Box]) – [units = um]. Size in x, y, and z directions.

• name (ConstrainedStrValue) – Unique name for the lumped element.

• num_grid_cells (Optional[PositiveInt] = 3) – Number of mesh grid cells associated with the lumped element along each direction. Used in generating the suggested list of MeshOverrideStructure objects. A value of None will turn off mesh refinement suggestions.

• voltage_axis (Literal[0, 1, 2]) – Specifies the axis along which the component is oriented and along which the associated voltage drop will occur. Must be in the plane of the element.

• snap_perimeter_to_grid (bool = True) – When enabled, the perimeter of the lumped element is snapped to the simulation grid, which improves accuracy when the number of grid cells is low within the element. Sides of the element perpendicular to the voltage_axis are snapped to grid boundaries, while the sides parallel to the voltage_axis are snapped to grid centers. Lumped elements are always snapped to the nearest grid boundary along their normal_axis, regardless of this option.

• network (Union[RLCNetwork, AdmittanceNetwork]) – The linear element produces an equivalent medium that emulates the voltage-current relationship described by the network field.

Notes

Implementation is based on the equivalent medium introduced by [1].

References

[1]

J. A. Pereda, F. Alimenti, P. Mezzanotte, L. Roselli and R. Sorrentino, “A new algorithm for the incorporation of arbitrary linear lumped networks into FDTD simulators,” IEEE Trans. Microw. Theory Tech., vol. 47, no. 6, pp. 943-949, Jun. 1999.

Example

>>> RL_series = RLCNetwork(resistance=75,
...                        inductance=1e-9,
...                        network_topology="series"
...             )
>>> linear_element = LinearLumpedElement(
...                         center=[0, 0, 0],
...                         size=[2, 0, 3],
...                         voltage_axis=0,
...                         network=RL_series,
...                         name="LumpedRL"
...                   )

See also

Notebooks:

• Using lumped elements in Tidy3D simulations

Attributes

attrs

Methods

admittance(freqs)	Returns the admittance of this lumped element at the frequencies specified by freqs.
impedance(freqs)	Returns the impedance of this lumped element at the frequencies specified by freqs.
to_structure([grid])	Converts the LinearLumpedElement object to a Structure ready to be added to the Simulation

Inherited Common Usage

network

to_structure(grid=None)

Converts the LinearLumpedElement object to a Structure ready to be added to the Simulation

admittance(freqs)

Returns the admittance of this lumped element at the frequencies specified by freqs.

Note

Admittance is returned using the physics convention for time-harmonic fields \(\exp{-j \omega t}\), so the imaginary part of the admittance will have an opposite sign compared to the expected value when using the engineering convention.

impedance(freqs)

Returns the impedance of this lumped element at the frequencies specified by freqs.

Note

Impedance is returned using the physics convention for time-harmonic fields \(\exp{-j \omega t}\), so the imaginary part of the impedance will have an opposite sign compared to the expected value when using the engineering convention.

__hash__()

Hash method.