HFSS: spiral inductor

This example shows how you can use PyAEDT to create a spiral inductor, solve it, and plot results.

Perform required imports

Perform required imports.

import os
import pyaedt

project_name = pyaedt.generate_unique_project_name(project_name="spiral")

Set AEDT version

Set AEDT version.

aedt_version = "2024.1"

Set non-graphical mode

Set non-graphical mode. You can set non_graphical either to True or False.

non_graphical = False

Launch HFSS

Launch HFSS 2023 R2 in non-graphical mode and change the units to microns.

hfss = pyaedt.Hfss(version=aedt_version, non_graphical=non_graphical, design="A1",
                   new_desktop=True)
hfss.solution_type = "Modal"
hfss.modeler.model_units = "um"
p = hfss.modeler

Define variables

Define input variables. You can use the values that follow or edit them.

rin = 10
width = 2
spacing = 1
thickness = 1
Np = 8
Nr = 10
gap = 3
hfss["Tsub"] = "6" + hfss.modeler.model_units

Standardize polyline

Standardize the polyline using the create_line method to fix the width, thickness, and material.

def create_line(pts):
    p.create_polyline(pts, material="copper", xsection_type="Rectangle", xsection_width=width,
                      xsection_height=thickness)

Create spiral inductor

Create the spiral inductor. This spiral inductor is not parametric, but you could parametrize it later.

ind = hfss.modeler.create_spiral(
    internal_radius=rin,
    width=width,
    spacing=spacing,
    turns=Nr,
    faces=Np,
    thickness=thickness,
    material="copper",
    name="Inductor1",
)

Center return path

Center the return path.

x0, y0, z0 = ind.points[0]
x1, y1, z1 = ind.points[-1]
create_line([(x0 - width / 2, y0, -gap), (abs(x1) + 5, y0, -gap)])
p.create_box([x0 - width / 2, y0 - width / 2, -gap - thickness / 2], [width, width, gap + thickness], material="copper")

<pyaedt.modeler.cad.object3d.Object3d object at 0x00000187CD4B55A0>

Create port 1

Create port 1.

p.create_rectangle(orientation=pyaedt.constants.PLANE.YZ,
                   origin=[abs(x1) + 5, y0 - width / 2, -gap - thickness / 2],
                   sizes=[width, "-Tsub+{}{}".format(gap, hfss.modeler.model_units)],
                   name="port1"
                   )
hfss.lumped_port(assignment="port1", integration_line=pyaedt.constants.AXIS.Z)

<pyaedt.modules.Boundary.BoundaryObject object at 0x00000187CD4B5F00>

Create port 2

Create port 2.

create_line([(x1 + width / 2, y1, 0), (x1 - 5, y1, 0)])
p.create_rectangle(pyaedt.constants.PLANE.YZ, [x1 - 5, y1 - width / 2, -thickness / 2],
                   [width, "-Tsub"],
                   name="port2")
hfss.lumped_port(assignment="port2", integration_line=pyaedt.constants.AXIS.Z)

<pyaedt.modules.Boundary.BoundaryObject object at 0x00000187C8100400>

Create silicon substrate and ground plane

Create the silicon substrate and the ground plane.

p.create_box([x1 - 20, x1 - 20, "-Tsub-{}{}/2".format(thickness, hfss.modeler.model_units)],
             [-2 * x1 + 40, -2 * x1 + 40, "Tsub"], material="silicon")

p.create_box([x1 - 20, x1 - 20, "-Tsub-{}{}/2".format(thickness, hfss.modeler.model_units)],
             [-2 * x1 + 40, -2 * x1 + 40, -0.1], material="PEC")

<pyaedt.modeler.cad.object3d.Object3d object at 0x00000187C8100700>

Assign airbox and radiation

Assign the airbox and the radiation.

box = p.create_box(
    [x1 - 20, x1 - 20, "-Tsub-{}{}/2 - 0.1{}".format(thickness, hfss.modeler.model_units, hfss.modeler.model_units)],
    [-2 * x1 + 40, -2 * x1 + 40, 100], name="airbox", material="air")

hfss.assign_radiation_boundary_to_objects("airbox")

<pyaedt.modules.Boundary.BoundaryObject object at 0x00000187C81030D0>

Assign material override

Assign a material override so that the validation check does not fail.

hfss.change_material_override()

True

Plot model

Plot the model.

hfss.plot(show=False, output_file=os.path.join(hfss.working_directory, "Image.jpg"), plot_air_objects=False)

<pyaedt.generic.plot.ModelPlotter object at 0x00000187CD4B4490>

Create setup

Create the setup and define a frequency sweep to solve the project.

setup1 = hfss.create_setup(name="setup1")
setup1.props["Frequency"] = "10GHz"
hfss.create_linear_count_sweep(setup="setup1", units="GHz", start_frequency=1e-3, stop_frequency=50,
                               num_of_freq_points=451, sweep_type="Interpolating")
hfss.save_project()
hfss.analyze()

True

Get report data

Get report data and use the following formulas to calculate the inductance and quality factor.

L_formula = "1e9*im(1/Y(1,1))/(2*pi*freq)"
Q_formula = "im(Y(1,1))/re(Y(1,1))"

Create output variable

Create output variable

hfss.create_output_variable("L", L_formula, solution="setup1 : LastAdaptive")

True

Plot calculated values in Matplotlib

Plot the calculated values in Matplotlib.

data = hfss.post.get_solution_data([L_formula, Q_formula])
data.plot(curves=[L_formula, Q_formula], formula="re", x_label="Freq", y_label="L and Q")

<Figure size 2000x1000 with 1 Axes>

Export results to csv file

Export results to csv file

data.export_data_to_csv(os.path.join(hfss.toolkit_directory, "output.csv"))

True

Save project and close AEDT

Save the project and close AEDT.

hfss.save_project(project_name)
hfss.release_desktop()

True