Lumped Ports And Elements

LumpedPort represents a planar, uniform-current RF excitation with a fixed impedance termination.

from flex_rf.tidy3d import LumpedPort

my_port_1 = LumpedPort(
    name="My Port 1",
    center=(0, 0, 0),
    size=(0, port_width, port_height),
    voltage_axis=2,
    impedance=50,
)

A lumped port must be planar, with exactly one zero-size dimension. Only axis-aligned planes are supported. If you need a narrow port, provide a small but finite width along the lateral axis. Only real impedance values are supported.

Lumped ports and elements are approximations. Use them when the port or element is much smaller than the wavelength of interest, typically lambda / 10. If the excitation is adjacent to an intentional waveguide or transmission line, a Wave Port or TerminalWavePort is often more accurate.

Coaxial Lumped Ports

CoaxialLumpedPort represents an analytical coaxial field source.

from flex_rf.tidy3d import CoaxialLumpedPort

my_coaxial_port_1 = CoaxialLumpedPort(
    name="My Coaxial Port 1",
    center=(0, 0, 0),
    inner_diameter=1000,
    outer_diameter=2000,
    normal_axis=0,
    direction="+",
    impedance=50,
)

Because CoaxialLumpedPort injects an analytical field source, the connected structure should match the physical port dimensions. Geometry mismatch can create reflections and inaccurate results.

Lumped Elements

Use LumpedResistor for a simple resistive element.

from flex_rf.tidy3d import LumpedResistor

my_resistor = LumpedResistor(
    name="My resistor",
    center=(0, 0, 0),
    size=(0, element_width, element_height),
    voltage_axis=2,
    resistance=50,
)

Use LinearLumpedElement with an RLCNetwork for more general RLC networks.

from flex_rf.tidy3d import LinearLumpedElement, RLCNetwork

my_lumped_element = LinearLumpedElement(
    name="My lumped element",
    center=(0, 0, 0),
    size=(0, element_width, element_height),
    voltage_axis=2,
    network=RLCNetwork(resistance=50, inductance=1e-9),
)

Add lumped elements to the lumped_elements field of the base simulation.

from flex_rf.tidy3d import Simulation

my_simulation = Simulation(
    lumped_elements=[my_resistor, my_lumped_element],
    # Other simulation fields.
)

Related API Symbols

Symbol	Purpose
LumpedPort	Rectangular planar lumped port.
CoaxialLumpedPort	Analytical coaxial lumped port.
LumpedResistor	Rectangular planar resistor.
CoaxialLumpedResistor	Coaxial resistor.
LinearLumpedElement	General linear lumped element backed by a network model.
RLCNetwork	Simple RLC network model.
AdmittanceNetwork	General admittance network model.

Related Pages

Page	Why open it
Terminal Component Modeler	Use lumped ports in multiport component models.
Wave Ports	Use modal ports for waveguides and transmission lines.
Layer-Based Grid Refinement	Refine grids around planar traces and lumped elements.