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 non-graphical mode

Set non-graphical mode. "PYAEDT_NON_GRAPHICAL" is needed to generate documentation only. You can set non_graphical either to True or False.

non_graphical = os.getenv("PYAEDT_NON_GRAPHICAL", "False").lower() in ("true", "1", "t")

Launch HFSS

Launch HFSS 2022 R2 in non-graphical mode and change the units to microns.

hfss = pyaedt.Hfss(specified_version="2022.2", non_graphical=non_graphical, designname="A1")
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
Tsub = 6

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, xsection_type="Rectangle", xsection_width=width, xsection_height=thickness, matname="copper")

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), matname="copper")

<pyaedt.modeler.cad.object3d.Object3d object at 0x0000028BF4FC5DF0>

Create port 1

Create port 1.

p.create_rectangle(csPlane=pyaedt.constants.PLANE.YZ,
                   position=(abs(x1) + 5, y0 - width / 2, -gap - thickness / 2),
                   dimension_list=(width, -Tsub + gap),
                   name="port1"
                   )
hfss.create_lumped_port_to_sheet(sheet_name="port1", axisdir=pyaedt.constants.AXIS.Z)

<pyaedt.modules.Boundary.BoundaryObject object at 0x0000028BEC0F6520>

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.create_lumped_port_to_sheet(sheet_name="port2", axisdir=pyaedt.constants.AXIS.Z)

<pyaedt.modules.Boundary.BoundaryObject object at 0x0000028BEC45B130>

Create silicon substrate and ground plane

Create the silicon substrate and the ground plane.

p.create_box([x1 - 20, x1 - 20, -Tsub - thickness / 2], [-2 * x1 + 40, -2 * x1 + 40, Tsub], matname="silicon")

p.create_box([x1 - 20, x1 - 20, -Tsub - thickness / 2], [-2 * x1 + 40, -2 * x1 + 40, -0.1], matname="PEC")

<pyaedt.modeler.cad.object3d.Object3d object at 0x0000028BEBD0EB80>

Assign airbox and radiation

Assign the airbox and the radiation.

box = p.create_box(
    [x1 - 20, x1 - 20, -Tsub - thickness / 2 - 0.1], [-2 * x1 + 40, -2 * x1 + 40, 100], name="airbox", matname="air"
)

hfss.assign_radiation_boundary_to_objects("airbox")

<pyaedt.modules.Boundary.BoundaryObject object at 0x0000028BF4DC1070>

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, export_path=os.path.join(hfss.working_directory, "Image.jpg"), plot_air_objects=False)

<pyaedt.generic.plot.ModelPlotter object at 0x0000028BEC0F6820>

Create setup

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

setup1 = hfss.create_setup(setupname="setup1")
setup1.props["Frequency"] = "10GHz"
hfss.create_linear_count_sweep(setupname="setup1", unit="GHz", freqstart=1e-3, freqstop=50, num_of_freq_points=451,
                               sweep_type="Interpolating")
hfss.save_project()
hfss.analyze_all()

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))"

Plot calculated values in Matplotlib

Plot the calculated values in Matplotlib.

x = hfss.post.get_solution_data([L_formula, Q_formula])
x.plot(curves=[L_formula, Q_formula], math_formula="re", xlabel="Freq", ylabel="L and Q")

<Figure size 2000x1000 with 1 Axes>

Save project and close AEDT

Save the project and close AEDT.

hfss.save_project(project_name)
hfss.release_desktop()

True