EM.Libera Tutorial Lesson 3: Analyzing Wire Antennas - Revision history

Kazem Sabet: Blanked the page

2015-11-10T03:30:40Z

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Kazem Sabet: /* Running a Uniform Frequency Sweep */

2015-11-09T23:55:09Z

‎Running a Uniform Frequency Sweep

Kazem Sabet: /* Running an Adaptive Frequency Sweep */

2015-11-09T23:53:44Z

‎Running an Adaptive Frequency Sweep

Kazem Sabet: /* Running an Adaptive Frequency Sweep */

2015-11-09T23:53:22Z

‎Running an Adaptive Frequency Sweep

Kazem Sabet: /* Running a Uniform Frequency Sweep */

2015-11-09T23:52:45Z

‎Running a Uniform Frequency Sweep

Kazem Sabet at 23:22, 9 November 2015

2015-11-09T23:22:06Z

Kazem Sabet: /* Defining the Gap Source and Project Observables */

2015-11-09T23:19:49Z

‎Defining the Gap Source and Project Observables

Kazem Sabet: /* Running the Wire MoM Simulation */

2015-11-09T23:19:21Z

‎Running the Wire MoM Simulation

Kazem Sabet: /* Running the Wire MoM Simulation */

2015-11-09T23:18:37Z

‎Running the Wire MoM Simulation

Kazem Sabet at 23:14, 9 November 2015

2015-11-09T23:14:01Z

@@ Line 162: / Line 162: @@
 ==Running a Uniform Frequency Sweep==
-[[Image:WMOM13.png|thumb|350px|The MoM3D Module's Run dialog with Wire MoM solver and Frequency Sweep selected.]]
+[[Image:MOMTUT3 21.png|thumb|400px|The MoM3D Module's Run dialog with Wire MoM solver and Frequency Sweep selected.]]
 To examine the frequency response of the dipole antenna, that is its port characteristics as a functions of frequency, you need to perform a frequency sweep of our structure.
 Click the <b>Run</b> [[Image:fdtd_runb.png]] Button of the Simulate Toolbar to open up the Simultion Run Dialog. Select the "Frequency Sweep" option from the drop-down list labeled "Simulation Mode". <u>Make sure you have selected the "Wire MoM" option for "Engine Type"</u>. Then, click on the <b>Settings</b> button next to the Simulation Mode drop-down list. This opens up the Frequency Settings dialog.
@@ Line 175: / Line 175: @@
 <tr>
 <td>
-[[Image:MOMTUT3 15.png|thumb|350px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
+[[Image:MOMTUT3 15.png|thumb|400px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
 </td>
 </tr>
@@ Line 183: / Line 183: @@
 <tr>
 <td>
-[[Image:MOMTUT3 16.png|thumb|350px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
+[[Image:MOMTUT3 16.png|thumb|500px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
 </td>
 </tr>
@@ Line 191: / Line 191: @@
 <tr>
 <td>
-[[Image:MOMTUT3 17.png|thumb|350px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
+[[Image:MOMTUT3 17.png|thumb|500px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
 </td>
 </tr>

@@ Line 207: / Line 207: @@
 <tr>
 <td>
-[[Image:MOMTUT3 18.png|thumb|500px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
+[[Image:MOMTUT3 18.png|thumb|400px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
 </td>
 </tr>

@@ Line 207: / Line 207: @@
 <tr>
 <td>
-[[Image:WMOM18.png|thumb|350px|The Frequency Sweep Settings dialog with the Adaptive Sweep option selected.]]
+[[Image:MOMTUT3 18.png|thumb|500px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
 </td>
 <td>
-[[Image:WMOM19.png|thumb|350px|Plot of Magnitude and Phase of S<sub>11</sub> vs. frequency in EM.Grid.]]
+[[Image:MOMTUT3 20.png|thumb|500px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
 </td>
 </tr>
 </table>
 {{EMCUBE directory}}
 [[EM.Cube  | Back to EM.Cube Wiki Main Page]]

@@ Line 175: / Line 175: @@
 <tr>
 <td>
-[[Image:WMOM14.png|thumb|350px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
+[[Image:MOMTUT3 15.png|thumb|350px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
 </td>
 <td>
-[[Image:WMOM16.png|thumb|350px|Plot of Magnitude and Phase of S<sub>11</sub> vs. frequency in EM.Grid.]]
+[[Image:MOMTUT3 16.png|thumb|350px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
 </td>
 <td>
-[[Image:WMOM17.png|thumb|350px|Plot of Magnitude and Phase of Z<sub>11</sub> vs. frequency in EM.Grid.]]
+[[Image:MOMTUT3 17.png|thumb|350px|The Frequency Sweep Settings dialog with the Uniform Sweep option selected.]]
 </td>
 </tr>

@@ Line 1: / Line 1: @@
-{{projectinfo|Tutorial| Analyzing Wire Antennas |WMOM12.png|In this project, wire dipole and loop antennas are modeled and analyzed.|
+{{projectinfo|Tutorial| Analyzing Wire Antennas |MOMTUT3 12.png|In this project, wire dipole and loop antennas are modeled and analyzed.|
 *[[CubeCAD]]
-*Visualization
+*Line Object
-*Gap Sources
+*Wire Dipole
-*S-[[Parameters]]
+*Wire MoM Analysis
-*Far Fields
+*Gap Source
 |All versions|{{download|http://www.emagtech.com|EM.Libera Lesson 3|[[EM.Cube]] 15.9}} }}
@@ Line 152: / Line 156: @@
 <td>
 [[Image:MOMTUT3 12.png|thumb|550px|The total 3D radiation pattern of the half-wave dipole antenna.]]
 </td>
 </tr>

@@ Line 71: / Line 71: @@
 </table>
-==Defining the Gap Source and Project Observables ==
+==Defining the Gap Source & Project Observables ==
 A dipole antenna can be excited using a gap source, which is the simplest source type in [[EM.Libera]]. A gap source can be placed on a line object (line gap), or on a rectangle strip object (strip gap). The line gap is intended for Wire MoM simulation, while the strip gap is intended for Surface MoM simulation. A line gap source creates an infinitesimal gap on the line and connects a voltage source across the gap. To define a gap source, right-click on the <b>Gap Sources</b> item in the “Sources” section of the navigation tree, and select <b>Insert New Line Gap Source…</b> The Line Gap Source Dialog opens up.

@@ Line 141: / Line 141: @@
 <tr>
 <td>
-[[Image:MOMTUT3 11.png|thumb|500px|The total current distribution on the wire dipole.]]
+[[Image:MOMTUT3 11.png|thumb|400px|The total current distribution on the wire dipole.]]
 </td>
 </tr>
 </table>
-Next, visualize the 3D radiation pattern of the dipole antenna. You will see the familiar donut shape with a directivity of 1.64.
+Next, visualize the 3D radiation pattern of the dipole antenna. You will see the familiar donut shape with a directivity of 1.623.
 <table>
 <tr>
 <td>
-[[Image:MOMTUT3 12.png|thumb|500px|The total 3D radiation pattern of the half-wave dipole antenna.]]
+[[Image:MOMTUT3 12.png|thumb|550px|The total 3D radiation pattern of the half-wave dipole antenna.]]
 </td>
 </tr>

@@ Line 117: / Line 117: @@
 ==Running the Wire MoM Simulation==
-[[Image:MOMTUT3 13.png|thumb|350px|The EM.Libera's Run dialog with Wire MoM solver and Single-Frequency Analysis selected.]]
+[[Image:MOMTUT3 13.png|thumb|500px|The EM.Libera's Run dialog with Wire MoM solver and Single-Frequency Analysis selected.]]
 At this time, your project is ready for the Wire MoM simulation of your dipole antenna structure. For wire structures, [[EM.Libera]] generates a wireframe mesh. It automatically detects whether your physical structure requires a surface mesh or a wireframe mesh. Open the Mesh Settings Dialog and change the value of '''Mesh Density''' to 30 cells per wavelength.
@@ Line 136: / Line 136: @@
 Z11: 77.464068 +41.698638j
 ==Viewing the Simulation Results==

@@ Line 115: / Line 115: @@
 </table>
-==Mesh Generation==
+==Running the Wire MoM Simulation==
-[[Image:WMOM8.png|thumb|400px|The Mesh Settings dialog.]]
+[[Image:MOMTUT3 13.png|thumb|350px|The EM.Libera's Run dialog with Wire MoM solver and Single-Frequency Analysis selected.]]
-[[EM.Cube]] has several types of mesh generators that are used to discretize the physical structure for the numerical solution of [[Maxwell's Equations|Maxwell's equations]]. [[EM.Cube]]'s [[MoM3D Module]] has two mesh generators: one for the Wire MoM solver and the other for the Surface MoM solver. The Wire MoM mesh generator discretizes line objects into a number of linear cells. It converts [[Curve Objects|curve objects]] first into polylines and then subdivides each side of the resulting polylines. The Wire MoM mesh generator creates a wireframe version of surface and [[Solid Objects|solid objects]]. The wireframe structure indeed consists of a set of interconnected wire segments. The current continuity is enforced at the joint shared among several interconnected wire segments. The Surface MoM mesh generator, on the other hand, creates a triangular surface mesh of surface and [[Solid Objects|solid objects]]. It ignores any line or [[Curve Objects|curve objects]].
+At this time, your project is ready for the Wire MoM simulation of your dipole antenna structure. For wire structures, [[EM.Libera]] generates a wireframe mesh. It automatically detects whether your physical structure requires a surface mesh or a wireframe mesh. Open the Mesh Settings Dialog and change the value of '''Mesh Density''' to 30 cells per wavelength.
-−
-You can control the mesh resolution in two ways. The first method is to set the "Mesh Density" in the form of the number of cells per wavelength. In this case, your mesh will be frequency dependent. For example, if you set the mesh density to 10 cells per wavelength, the number of cells on a line object of fixed length will increase as the frequency increases. At an operational frequency of 1GHz, the wavelength is 300mm. Therefore, with this mesh density, you will have a total of 5 cells across your 150mm long dipole antenna. Now consider an operational frequency of 2GHz with a corresponding free-space wavelength of 150mm. With the same mesh density, your dipole antenna will have 10 cells at 2GHz. The second method of controlling the mesh is by setting a fixed "Edge Length" for the mesh cells. The edge length is set in the project units. A mesh of this kind will be frequency-independent. By default, the "Mesh Resolution" is set in terms of "Density" with a default value of 10 cells per wavelength.
-−
-−
-The mesh properties can be accessed by clicking the <b>Mesh Settings</b> [[Image:fdtd_meshsettings.png]] button of the Simulate Toolbar (or using the keyboard shortcut <b>Ctrl+G</b> or via the menu <b>Simulate &rarr; Discretization &rarr; Mesh Settings</b>). For this tutorial, set the mesh type to "Wire MoM Mesh", keep the default "Density" option and set its value to 30 cells per wavelength. In this case, at 1GHz your dipole antenna will have 15 cells across it.
 {{Note|A high mesh density is recommended for resonant structures and for better visualization of current distributions.}}
-To view the mesh, click the <b>Show/Generate Mesh</b> [[Image:fdtd_meshshow.png]] button of the Simulate Toolbar (or alternatively use the keyboard shortcut <b>Ctrl+M</b>). For this particular project, the mesh view does not reveal much because the mesh of a vertical line object conforms to wire itself. In general, the mesh view shows how the simulation engine sees your physical structure.
+Click the <b>Run</b> [[Image:fdtd_runb.png]] Button of the Simulate Toolbar to open up the Simulation Run Dialog. You will see that the "Simulation Engine Type" is automatically set to "Wire MoM Solver".
-==Defining Project Observables==
+Or alternatively, use the keyboard shortcut <b>Ctrl+R</b>, or the menu <b>Simulate &rarr; Run…</b> The simplest simulation mode in [[EM.Cube]] is “Analysis”. In this mode, your physical structure is taken “As Is” and its mesh is passed to the Wire MoM simulation engine, along with the necessary information regarding the sources and observables. Since MoM simulations are frequency-domain, first you will run a "Single-Frequency Analysis". Select this option from the drop-down list labeled "Simulation Mode". Make sure you have selected the "Wire MoM" option for "Engine Type".
-Project observables are output quantities that you would like to compute at the end of an FDTD simulation. By default, the Wire MoM solver does not generate any output data unless you define one or more project observables before you start a simulation.
+Run a MoM simulation of your dipole antenna. Once the simulation is complete, the output window will report the calculated S, Z and Y parameters:
-<b><u>Current Distribution</u></b>
+S11: 0.291310 +0.231841j
-Current distribution observables are used to visualize the linear currents on the wires or wireframe structures. To define a current distribution observable, right click on the <b>Current Distributions</b> item in the “Observables” section of the Navigation Tree and select <b>Insert New Observable…</b> This opens up the Current Distribution Dialog. Keep all the default options and close the dialog. A new entry CD_1 is added to the Navigation Tree.
+S11(dB): -8.581999
-<b><u>Radiation Patterns</u></b>
+Y11: 0.010009 -0.005388j
-To plot the radiation patterns of a radiating structure, you need to define a far field observable. To define a far field observable, right click on the <b>Far Fields</b> item in the <b>Observables</b> section of the Navigation Tree, and select <b>Insert New Radiation Pattern…</b> In general, you can accept the default values, unless a special case is being analyzed.
+Z11: 77.464068 +41.698638j
 ==Viewing the Simulation Results==