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Glossary of EM.Cube's Sources & Devices

13,470 bytes added, 00:36, 19 February 2021

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[[Image:SOURCE MAN2.png|thumb|left|480px|The distributed source dialog.]]

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== Filamentary Current Source ==

ICON: [[File:hertz_src_icon.png]]

MODULE: [[EM.Tempo]]

FUNCTION: Places a filamentary current source at a specified location in the project workspace

TO DEFINE A FILAMENTARY CURRENT SOURCE:

# Right-click on the '''Filamentary Current Sources''' item in the navigation tree.

# Either select '''Insert New Hertzian Short Dipole Source...''' or select '''Insert New Long Wire Current Source...''' to open up the Filamentary Current Source Dialog.

# By default, the filamentary current source is placed at the origin of coordinates. You can modify the source's center coordinates.

# The "Current Distribution Profile" dropdown list provides four options: Hertzian Short Dipole Radiator, Uniform Long Wire Current, Triangular Long Wire Current and Sinusoidal Long Wire Current. Select the desired type.

# By default, a vertical Z-directed current is defined. You can change the components of the unit vector along the dipole to reorient it along any arbitrary direction. In the case of a long wire current source, it has to be oriented along one of the three principal axes. In other words, only one of uX, uY or uZ components must be one and the other two must be zero.

# You may also modify the current amplitude and phase as well as the filament length.

# Click the '''OK''' button of the dialog to return to the project workspace.

NOTES, SPECIAL CASES OR EXCEPTIONS: A filamentary current source with Hertzian short dipole radiator profile is equivalent to [[#Hertzian_Short_Dipole_Source | Hertzian Short Dipole Source]] in the other computational modules of [[EM.Cube]].

PYTHON COMMAND: None

SHORT DIPOLE PARAMETERS

{| class="wikitable"

! scope="col"| Parameter Name

! scope="col"| Value Type

! scope="col"| Units

! scope="col"| Default Value

! scope="col"| Notes

! scope="row" | x0

| real numeric

| project units

| 0

| X-coordinate of source location

! scope="row" | y0

| real numeric

| project units

| 0

| Y-coordinate of source location

! scope="row" | z0

| real numeric

| project units

| 0

| Z-coordinate of source location

! scope="row" | amplitude

| real numeric

| Amperes

| 1

| amplitude of filamentary current

! scope="row" | phase

| real numeric

| degrees

| 0

| phase of filamentary current

! scope="row" | length

| real numeric

| project units

| 3

| filament length

! scope="row" | uX

| real numeric

| -

| 0

| X-component of unit direction vector

! scope="row" | uY

| real numeric

| -

| 0

| Y-component of unit direction vector

! scope="row" | uZ

| real numeric

| -

| 1

| Z-component of unit direction vector

<table>

<tr>

<td>

[[Image:SOURCE_Filament.png|thumb|left|480px|The filamentary current source dialog.]]

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</tr>

</table>

== Gaussian Beam ==

ICON: [[File:gauss_icon.png]]

MODULE: [[EM.Tempo]]

FUNCTION: Defines a focused Gaussian beam source with specified incidence angles, polarization, beam focus point and beam radius

TO DEFINE A GAUSSIAN BEAM:

# Right-click on the '''Plane Waves''' item in the navigation tree.

# Select '''Insert New Source...''' to open up the Plane Wave Dialog.

# By default, a TMz-polarized plane wave source is defined with normal incidence along the negative Z-axis.

# You can change the '''Polarization''' type and incident '''Theta''' and '''Phi''' angles in the spherical coordinate system.

# Click the '''OK''' button of the dialog to return to the project workspace.

NOTES, SPECIAL CASES OR EXCEPTIONS: Unlike plane waves, a Gaussian beam is a localized field. By default, the dominant fundamental Hermite-Gauss mode H<sub>00</sub> is assumed. You can define a higher-order Hermite-Gauss mode by assigning nonzero values for the modal indices '''p''' and '''q'''.

{{note|The beam radius has to be at least λ<sub>0</sub>/π; otherwise, strong fields appear outside the excitation box.}}

PYTHON COMMAND: gauss_beam(label,theta,phi,polarization,focus_x,focus_y,focus_z,radius,p_mode,q_mode)

GAUSSIAN BEAM PARAMETERS

{| class="wikitable"

! scope="col"| Parameter Name

! scope="col"| Value Type

! scope="col"| Units

! scope="col"| Default Value

! scope="col"| Notes

! scope="row" | polarization

| List: TMz, TEz, Custom Linear

| -

| TMz

| select one of the linear or circular polarization types

! scope="row" | theta

| real numeric

| degrees

| 180

| incident elevation angle

! scope="row" | phi

| real numeric

| degrees

| 0

| incident azimuth angle

! scope="row" | focus_x

| real numeric

| project units

| 0

| X-coordinate of beam focus point

! scope="row" | focus_y

| real numeric

| project units

| 0

| Y-coordinate of beam focus point

! scope="row" | focus_z

| real numeric

| project units

| 0

| Z-coordinate of beam focus point

! scope="row" | radius

| real numeric

| project units

| 10

| beam waist radius

! scope="row" | p

| integer numeric

| -

| 0

| first index of Hermite-Gauss mode

! scope="row" | q

| integer numeric

| -

| 0

| second index of Hermite-Gauss mode

<table>

<tr>

<td>

[[Image:GaussBeam.png|thumb|left|480px|The Gaussian beam source dialog.]]

</td>

</tr>

<td>

[[Image:SOURCE MAN1.png|thumb|left|480px|The lumped source dialog.]]

</td>

</tr>

</table>

== Microstrip Port ==

ICON: [[File:mstrip_icon.png]]

MODULE: [[EM.Tempo]]

FUNCTION: Places a special distributed source of a specified height underneath one of the edges of a PEC rectangle strip object that is parallel to one of the three principal planes

TO DEFINE A MICROSTRIP PORT:

# Right-click on the '''Microstrip Ports''' item in the navigation tree of [[EM.Tempo]].

# Select '''Insert New Source...''' to open up the Microstrip Port Dialog.

# From the '''Host''' drop-down list, select a rectangle strip object. Note that only PEC rectangle strip objects parallel to one of the three principal planes are listed.

# You have to specify the height of the microstrip port, which is the same as the height of the microstrip's substrate.

# A microstrip port can be placed at one of the four edges of the host rectangle strip. You can select the desired location from the '''Edge''' drop-down list.

# Click the '''OK''' button of the dialog to return to the project workspace.

PYTHON COMMAND: microstrip_src(label,rect_object,height,edge[,magnitude,phase,resistance])

MICROSTRIP PORT PARAMETERS

{| class="wikitable"

! scope="col"| Parameter Name

! scope="col"| Value Type

! scope="col"| Units

! scope="col"| Default Value

! scope="col"| Notes

! scope="row" | height

| real numeric

| project units

| 1.5

| microstrip's substrate height

! scope="row" | resistance

| real numeric

| Ohms

| 50

| internal impedance of the distributed voltage source

<table>

<tr>

<td>

[[Image:SOURCE MAN3.png|thumb|left|480px|The microstrip port source dialog.]]

</td>

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<td>

[[Image:Lumped Par_RC.png|thumb|left|480px|The lumped device dialog with the Parallel RC device type selected.]]

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</table>

== Plane Wave ==

ICON: [[File:plane_wave_icon.png]]

MODULE: [[EM.Tempo]], [[EM.Illumina]], [[EM.Picasso]], [[EM.Libera]]

FUNCTION: Defines a plane wave source with specified incidence angles and polarization

TO DEFINE A PLANE WAVE:

# Right-click on the '''Plane Waves''' item in the navigation tree.

# Select '''Insert New Source...''' to open up the Plane Wave Dialog.

# By default, a TMz-polarized plane wave source is defined with normal incidence along the negative Z-axis.

# You can change the '''Polarization''' type and incident '''Theta''' and '''Phi''' angles in the spherical coordinate system.

# Click the '''OK''' button of the dialog to return to the project workspace.

NOTES, SPECIAL CASES OR EXCEPTIONS: In the case of a free-space background medium, the incident electric and magnetic fields of the plane wave source are given by:

:<math> \mathbf{E^{inc}(r)} = E_0 \mathbf{\hat{e}} e^{ -jk_0 \mathbf{\hat{k}\cdot r} } </math>

:<math> \mathbf{H^{inc}(r)} = \mathbf{\hat{k} \times \hat{e}} \frac{E_0}{\eta_0} e^{-jk_0 \mathbf{\hat{k} \cdot r} } </math>

where <math>\eta_0 = 120\pi</math> is the characteristic impedance of the free space, <math>\mathbf{\hat{k}}</math> is the unit propagation vector of the incident plane wave, and <math>\mathbf{\hat{e}}</math> is the polarization vector corresponding to the electric field of that wave.

In [[EM.Picasso]], your plane wave source is placed above a multilayer substrate structure. In that case, the incident plane wave bounces off the layered background structure and part of it also penetrates the substrate layers. The total incident field that is used to calculate the excitation vector is a superposition of the incident, reflected and transmitted plane waves at various regions of your planar structure:

:<math> \mathbf{E^{inc}(r)} = E_0 (\mathbf{\hat{e}_1} e^{ -jk_0 \mathbf{\hat{k}_1\cdot r} } + R \mathbf{\hat{e}_2} e^{ -jk_0 \mathbf{\hat{k}_2\cdot r} } ) </math>

:<math> \mathbf{H^{inc}(r)} = \frac{E_0}{\eta_0} ( \mathbf{\hat{k}_1 \times \hat{e}_1} e^{-jk_0 \mathbf{\hat{k}_1 \cdot r} } + R \mathbf{\hat{k}_2 \times \hat{e}_2} e^{-jk_0 \mathbf{\hat{k}_2\cdot r} } ) </math>

where <math>\mathbf{\hat{k}_1}</math> and <math>\mathbf{\hat{k}_2}</math> are the unit propagation vectors of the incident plane wave and the wave reflected off the topmost substrate layer, respectively, and <math>\mathbf{\hat{e}_1}</math> and <math>\mathbf{\hat{e}_2}</math> are the polarization vectors corresponding to the electric field of those waves. R is the reflection coefficient at the interface between the top half-space and the topmost substrate layer and has different values for the TM and TE polarizations.

PYTHON COMMAND: planewave(label,theta,phi,polarization)

PLANE WAVE PARAMETERS

{| class="wikitable"

! scope="col"| Parameter Name

! scope="col"| Value Type

! scope="col"| Units

! scope="col"| Default Value

! scope="col"| Notes

! scope="row" | polarization

| List: TMz, TEz, LCPz, RCPz, Custom Linear

| -

| TMz

| select one of the linear or circular polarization types

! scope="row" | theta

| real numeric

| degrees

| 180

| incident elevation angle

! scope="row" | phi

| real numeric

| degrees

| 0

| incident azimuth angle

<table>

<tr>

<td>

[[Image:Tempo L2 Fig4.png|thumb|left|480px|The plane wave source dialog.]]

</td>

</tr>

<td>

[[Image:Lumped MAN1.png|thumb|left|480px|The lumped device dialog with the resistor type selected.]]

</td>

</tr>

</table>

== Scattering Wave Port ==

ICON: [[File:waveport_src_icon.png]]

MODULE: [[EM.Picasso]]

FUNCTION: Creates an infinitesimal gap across a PEC rectangle strip object at a specified location and places an ideal voltage source with a series internal resistor

TO DEFINE A SCATTERING WAVE PORT:

# Right-click on the '''Scattering Wave Ports''' item in the navigation tree.

# Select '''Insert New Source...''' to open up the Wave Port Dialog.

# From the '''Host''' drop-down list, select a PEC rectangle strip object.

# By default, the wave port is placed at one end of the host rect strip object. The incident wave propagates along the host strip towards this end. You can change the direction of the incident wave. You can also modify the '''Offset''' parameter, which is measured from the endpoint of the host strip. This establishes the phase reference plane for computation of the scattering parameters.

# Click the '''OK''' button of the dialog to return to the project workspace.

NOTES, SPECIAL CASES OR EXCEPTIONS: A scattering wave port is made up of a gap source that is placed close to an open end of a rectangle strip representing a feed line. The other end of the line is typically connected to a planar structure of interest. in the process of planar mesh generation, [[EM.Picasso]] automatically extends the length of a port line that hosts a scattering wave port to about two effective wavelengths. This is done to provide enough length for formation of a clean standing wave current pattern. The effective wavelength of a transmission line for length extension purposes is calculated in a similar manner as for the planar mesh resolution. It is defined as <math>\lambda_{eff} = \tfrac{\lambda_0}{\sqrt{\varepsilon_{eff}}}</math>, where ε<sub>eff</sub> is the effective permittivity. For metal and conductive sheet traces, the effective permittivity is defined as the larger of the permittivities of the two substrate layers just above and below the metallic trace. For slot traces, the effective permittivity is defined as the mean (average) of the permittivities of the two substrate layers just above and below the metallic trace. The host port line must always be open from one end to allow for its length extension. You have to make sure that there are no objects standing on the way of the extended port line to avoid any unwanted overlaps.

PYTHON COMMAND: wave_port(label,rect_object,offset,is_negative[,amplitude,phase])

SCATTERING WAVE PORT PARAMETERS

{| class="wikitable"

! scope="col"| Parameter Name

! scope="col"| Value Type

! scope="col"| Units

! scope="col"| Default Value

! scope="col"| Notes

! scope="row" | direction

| List: pos, neg

| -

| pos

| direction of the incident wave

! scope="row" | offset

| real numeric

| project units

| 0

| distance between the source and the endpoint of the host strip object

! scope="row" | amplitude

| real numeric

| Volts

| 1

| amplitude of incident wave

! scope="row" | phase

| real numeric

| degrees

| 0

| phase of incident wave