At the end of a 3D MoM simualtion, EM.Libera generates a number of output data files that contain all the computed simulation data. The primary solution of the Wire MoM simulation engine consists of the linear electric currents on the wires and wireframe structures. The primary solution of the Surface MoM simulation engine consists of the electric and magnetic surface currents on the PEC and dielectric objects. EM.Libera currently offers the following types of observables (click on each type to learn more about it):
* '''Current Distributions''': Electric and magnetic surface current amplitude and phase on all metal and dielectric surfaces and electric current amplitude and phase on all wires
* '''Near-Field Distributions''': Electric and magnetic field amplitude and phase on specified planes and their central axes
* '''Port Characteristics''': S, Z and Y [[Parameters]] and Voltage Standing Wave Ratio (VSWR)
* '''Radiation Characteristics''': Radiation Patterns, Directivity, Total Radiated Power, Axial Ratio, Main Beam Theta and Phi, Radiation Efficiency, Half Power Beam Width (HPBW), Maximum Side Lobe Level (SLL), First Null Level (FNL), Front-to-Back Ratio (FBR), etc.
* '''Scattering Characteristics''': Bi-static and Mono-static Radar Cross Section (RCS)
* '''Current Distributions''': Electric and magnetic surface current amplitude and phase on all metal and dielectric surfaces and electric current amplitude and phase on all wires
* '''Near-Field Distributions''': Electric and magnetic field amplitude and phase on specified planes and their central axes
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=== Scattering Parameters and Port Characteristics ===
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If the project structure is excited by gap sources, and one or more ports have been defined, the Wire MoM engine calculates the scattering (S) [[parameters]] of the selected ports, all based on the port impedances specified in the project's "Port Definition". If more than one port has been defined in the project, the scattering matrix of the multiport network is calculated. The S [[parameters]] are written into output ASCII data files. Since these data are complex, they are stored as '''.CPX''' files. Every file begins with a header starting with "#". The admittance (Y) and impedance (Z) [[parameters]] are also calculated and saved in complex data files with '''.CPX''' file extensions. The voltage standing wave ratio of the structure at the first port is also computed and saved to a real data '''.DAT''' file.
You can plot If the port characteristics from the Navigation Tree. Right click on the '''Port Definition''' item in the '''Observables''' section of the Navigation Tree project structure is excited by gap sources, and select one of or more ports have been defined, EM.Libera calculates the items: '''Plot scattering (S ) [[Parametersparameters]]'''of the selected ports, all based on the port impedances specified in the project'''Plot Y [[Parameters]]''', '''Plot Z [[Parameters]]''', or '''Plot VSWR'''s "Port Definition".
[[Image:Info_icon.png|40px]] Click here to learn more about '''[[Data_Visualization_and_Processing#Computing_and_Graphing_Port_Characteristics | Computing and Graphing Port Characteristics]]'''.
[[Image:Info_icon.png|40px]] Click here to learn more about '''[[Data_Visualization_and_Processing#Rational_Interpolation_of_Port_Characteristics | Rational Interpolation of Scattering Parameters]]'''.
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=== Visualizing Current Distributions ===
[[Image:MOM10.png|thumb|350px|EM.Libera's Current Distribution dialog.]]
At Depending on the end types of a MoM3D simulationobjects present in your project workspace, [[EM.Cube|EM.CUBE]]'s Libera performs either a Surface MoM simulation or a Wire MoM engine generates a number of output data files that contain all the computed simulation data. The main output data are In the current distributions former case, the electric and far fields. You can easily examine the 3-D color-coded intensity plots of magnetic surface current distributions in the Project Workspace. Current distributions are visualized on all the wires and the magnitude and phase surface of the electric currents are plotted for all the PEC and dielectric objectscan be visualized. In order to view these currents, you must first define current sensors before running the Wire MoM simulation. To do thislatter case, right click on the '''Current Distributions''' item in the '''Observables''' section of the Navigation Tree and select '''Insert New Observable...'''. The Current Distribution Dialog opens up. Accept the default settings and close the dialog. A new current distribution node is added to the Navigation Tree. Unlike the [[Planar Module]], in the [[MoM3D Module]] you can define only one current distribution node in the Navigation Tree, which covers all the PEC object in the Project Workspace. After a Wire MoM simulation is completed, new plots are added under the current distribution node of the Navigation Tree. Separate plots are produced for the magnitude and phase of the linear wire electric currents. The magnitude maps are plotted on a normalized scale with all the minimum wires and maximum values displayed in the legend box. The phase maps are wireframe objects can be plotted in radians between -π and π.
[[Image:Info_icon.png|40px]] Click here to learn more about '''[[Data_Visualization_and_Processing#Visualizing_3D_Current_Distribution_Maps | Visualizing 3D Current Distribution Maps]]'''.
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=== Near Field Visualization ===
[[Image:MOM11.png|thumb|350px|EM.Libera's Field Sensor dialog.]]
EM.Libera allows you to visualize the near fields at a specific field sensor planeof arbitrary dimensions. Calculation of near fields is a post-processing process and may take a considerable amount of time depending on the resolution that you specify.
{{Note|Keep in mind that since EM.Libera uses MoM solvers, the calculated field value at the source point is infinite. As a result, the field sensors must be placed at adequate distances (at least one or few wavelengths) away from the scatterers to produce acceptable results.}}
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=== Computing Radiation Patterns ===
[[Image:MOM12.png|thumb|380px|EM.Libera's Radiation Pattern dialog.]]
Unlike the FDTD method, the method of moments does not need a far field box to perform near-to-far-field transformations. But you still You need to define a far field observable if you want to plot radiation patterns of your physical structure in EM.Libera. A far field can be defined by right clicking on the '''Far Fields''' item in the '''Observables''' section of the Navigation Tree and selecting '''Insert New Radiation Pattern...''' from the contextual menu. The Radiation Pattern dialog opens up. You can accept most of the default settings in this dialog. The Output Settings section allows you to change the '''Angle Increment''' for both Theta and Phi observation angles in the degrees. These [[parameters]] indeed set the resolution of far field calculations. The default values are 5 degrees. After closing the radiation pattern dialog, a far field entry immediately appears with its given name under the '''Far Fields''' item of the Navigation Tree and can be right clicked for further editing. After a 3D MoM simulation is finished, three radiation patterns plots are added to the far field entry in the Navigation Tree. These are the far field component in Theta direction, the far field component in Phi direction and the total far field.
[[Image:Info_icon.png|40px]] Click here to learn more about '''[[Maxwell%27s_Equations#Definition_of_the_Far_Radiation_Zone | Computing the Far Fields & Radiation Characteristics]]'''.
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=== Computing Radar Cross Section ===
[[Image:MOM13.png|thumb|380px|EM.Libera's Radar Cross Section dialog.]]