7

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HOBBIES POST-PROCESSING FOR VISUALIZING THE RESULTS

7.0 SUMMARY

Higher Order Basis Based Integral Equation Solver (HOBBIES) provides a powerful and user-friendly interface for post-processing, which enables users to visualize easily the output results. Corresponding to the parameters in the output settings introduced in Chapter 6, the 2D/3D radiation or scattering patterns, 2D/3D near-field cuts, Y/Z/S network parameters, and electric/magnetic currents can be viewed in post-processing.

The menus and toolbars for post-processing are introduced at the beginning of this chapter, followed by the visualization of the mesh and domains of a project. Users can view the quality of the mesh, along with the domain information. The difference between displaying domains with a model in pre-processing and post-processing, as described in Chapter 6, is that the domains are displayed with the mesh in the post-processing.

Users can also plot 2D/3D radiation and scattering patterns. For 2D radiation patterns, theta-cut planes (theta is constant), phi-cut planes (phi is constant), and frequency-cut planes (both theta and phi are constant) are available. These cuts are useful when users are interested in the fields at the theta, phi, or frequency-cut planes. Different polarizations can be calculated and viewed, including: left-handed/right-handed circular polarization, co-polarization and cross-polarization, and so on. Different quantities can be viewed for each component, which include the real and imaginary parts, magnitude, and phase. Network parameters, including the Y-, Z- and S-parameters, can be plotted if a simulation of Antenna Modes is performed. Also, electric/magnetic field distributions in a near-field zone or electric/magnetic currents are of interest to users. HOBBIES post-processing plots these results in a user friendly fashion for a quick display.

HOBBIES post-processing also enables users to customize a 2D/3D plot with options to change the graph color, show/hide the gridline, change the ranges, and so on. Detailed information is provided in the subsequent sections.

7.1 ENTERING POST-PROCESSING WINDOW

Menu: FilesPostprocess

Toolbar:

Select the FilesPostprocess menu, or click the icon in the Toolbar. This allows the user to enter the HOBBIES post-processing window. The post-processing window can also be accessed by clicking the Postprocess button in the Process Information window. This window appears when the simulation is finished as shown in Figure 7.1.

Figure 7.1. Process information window.

7.2 POST-PROCESSING WINDOW

7.2.1 Top Menu in Post-Processing Window

The top menu of the post-processing window is presented in this section (Figure 7.2).

Figure 7.2. Top menu of the HOBBIES post-processing window.

Each drop-down menu of the post-processing window is introduced next.

Files

The Files menu of the post-processing phase is similar to that in the pre-process phase. Users can read and save files, save screen images, return to the pre-process phase, or exit the program. The Files drop-down menu is shown in Figure 7.3.

View

This menu is the same as that in the HOBBIES main window (see Section 3.4.1 in Chapter 3).

HOBBIES Results

In this menu, users can choose which type of results to display. The results include Simulated Model, Radiation/Scattering pattern, Y/Z/S Parameters, Near-field, and Electric/Magnetic current. The HOBBIES Results drop-down menu is shown in Figure 7.4.

Configure

This menu allows users to choose the preferred options for a project, as shown in Figure 7.5, which is the same as that in the pre-process phase (see Section 3.4.1 in Chapter 3).

Help

This menu is the same as that in the HOBBIES main window (see Section 3.4.1 in Chapter 3).

Figure 7.3. Files menu.

Figure 7.4. HOBBIES Results menu.

Figure 7.5. Configure menu.

7.2.2 Toolbar in Post-Processing Window

The HOBBIES Toolbar in the post-processing window is shown in Figure 7.6. The functionality of the icons on the Toolbar is summarized in Figure 7.7 and Figure 7.8.

Figure 7.6. Toolbar of HOBBIES post-processing window.

Figure 7.7. Standard Toolbar and Information and Option Toolbar.

Figure 7.8. View Operation Toolbar and EM Toolbar.

The Standard Toolbar and View Operation Toolbar are just the same as in pre-processing window (refer to Section 3.4.3). The Info and Option Toolbar and EM Toolbar are introduced next.

Info and Option Toolbar

Display the number of nodes

Display the number of elements

Change render option: Normal, Flat, Smooth

Switch to transparent/opaque mode

EM Toolbar

Radiation/scattering pattern (2D) over a frequency band

Radiation/scattering pattern (2D)

Radiation/scattering pattern (3D)

Network parameters

Near-field distribution (2D)

Near-field distribution (3D)

Electric current distribution

Magnetic current distribution

7.2.3 Left Panel in Post-Processing Window

The Left Panel in the HOBBIES post-processing window provides corresponding options for each type of result. For example, the Left Panel for the Simulated Model contains the Domain information, as shown in Figure 7.9. The Left Panel will be described in detail in Section 7.3.

7.2.4 Mouse Menu

The Mouse Menu is the auxiliary menu, which appears by clicking the right mouse button on the HOBBIES post-processing screen, as shown in Figure 7.10. The Mouse Menu permits users to access quickly various image placement and viewing commands, to facilitate easy management of the project (refer to Section 3.4.2).

Figure 7.9. The Left Panel for a Simulated Model.

Figure 7.10. Right mouse button pop-up menu.

7.2.5 Command Line

The Command Line option (Figure 7.11) allows users to enter directly all executable HOBBIES commands, without accessing the commands through drop-down menus. See Command Line as described in Section 3.4.4.

Figure 7.11. Command line of post-processing.

7.3 EXAMPLE OF OPERATIONS IN POST-PROCESSING

In the post-processing window, users can view simulation results by selecting different options located in the HOBBIES Results drop-down menu. Users can also view HOBBIES results through the EM Toolbar, as described in Section 7.2.2.

7.3.1 Viewing the Simulated Models

Menu: HOBBIES ResultsSimulated Model

The simulated model is displayed when the user enters the post-processing window. Also, the simulated model can be shown by clicking the Simulated Model option from the HOBBIES Results menu, as demonstrated in Figure 7.12.

The Left Panel contains the Domain list. To show a particular domain, select the check box in the Domains list; to hide a particular domain, deselect the check box.

To change the color of a particular domain, double click the Color field in the Domains list, select the color in the Select color window (Figure 7.13), and click OK.

To change the displayed domain from the Opaque mode to the Transparent mode, click the Trans status icon in the Domains list and the icon (Opaque) changes to (Transparent). The model in Transparent mode is shown in Figure 7.14. Click the icon again and the domain is changed back to the Opaque mode.

Figure 7.12. Simulated model shown in the post-processing window.

Figure 7.13. Color window.

Figure 7.14. View domains with mesh in Transparent mode.

While viewing the structure, the user can choose different display styles. Click the icon in the Style column; there are several structure display styles available in the drop-down list (Figure 7.15):

: the structure is transparent.

: the structure is opaque.

: the mesh is transparent.

: the mesh is opaque.

: the structure and mesh are transparent.

: the contour of the structure is displayed.

: the mesh is displayed.

: the nodes (including mesh nodes) are displayed.

: the contour and nodes (including mesh nodes) are displayed.

Figure 7.15. View of domains using different display styles.

7.3.2 Viewing the Radiation or Scattering Patterns

The operations for 2D and 3D scattering patterns are very similar to those for 2D and 3D radiation patterns. This section focuses mainly on the operations for radiation patterns for demonstration purposes.

7.3.2.1 2D Radiation or Scattering Patterns

Menu: HOBBIES ResultsRadiation (2D) for Antenna Modes

Menu: HOBBIES ResultsScattering (2D) for Scatterer Modes

Toolbar:

Starting with a project that utilizes Antenna Modes as an example, click the Radiation (2D) option on the HOBBIES Results drop-down menu and a 2D radiation pattern is shown, as depicted in Figure 7.16. The Left Panel contains three tabs: Data, Options, and Range, which will be described next.

Figure 7.16. A 2D radiation pattern with the Left Panel.

• Data Tab in the Left Panel

The Data tab is the default tab in the Left Panel, which contains the 2D radiation results to be displayed. The Data tab with notations is shown in Figure 7.17.

A default legend for the current plot is set by checking the Automatic Title option, which will be described in detail in the Options tab section.

The Name field displays the name of the current project.

The Freq. drop-down list contains all the frequencies set in the project, as shown in Figure 7.18(a). The default frequency is the start frequency. To change the frequency, users can select one through the drop-down list or use the shortcuts and .

The Excit. drop-down list contains all the excitations set in the project, as shown in Figure 7.18(b). The default excitation is the first excitation. To change the excitation, users can select one through the drop-down list or use the shortcuts and . Note that the excitations in Antenna Modes are Generators.

Figure 7.17. Data tab in the Left Panel with notations for 2D radiation patterns.

Figure 7.18. Drop-down lists: (a) Frequency, (b) Excitation.

The Component box shows all electric field components to be displayed, which includes:

• E-Total: total radiation fields (default)
• E-Phi: phi-component of the radiation fields
• E-Theta: theta-component of the radiation fields
• Rc: right-circular component of the radiation fields
• Lc: left-circular component of the radiation fields
• Max.Lin: maximum linear polarization component of the radiation fields
• Min.Lin: minimum linear polarization component of the radiation fields
• Copolar: co-polarization component of the radiation fields
• Crosspolar: cross-polarization component of the radiation fields

The Quantity box shows different quantities for the displayed electric field component, which are:

• Real: real part of the field components
• Imaginary: imaginary part of the field components
• Magnitude: magnitude of the field components
• Phase: phase of the field components
• Gain: gain, in an unnamed unit, of the field components (default)
• Gain (dB): gain in dB of the field components
• Ellipticity: ellipticity of the field components
• Polar. Angle: polarization angle of the field components

The Independent Variable box contains all phi and theta angles in which the results have been calculated in the project. The Phi-cut option (default) is to display a radiation pattern versus theta angles for a selected phi angle, while the Theta-cut option is to display a radiation pattern versus phi angles for a selected theta angle. Phi (theta) angles can be selected in the corresponding drop-down list or changed through shortcuts and ( and ). The default angles are the start angles set in the output settings. Two-dimensional radiation patterns can be displayed in Cartesian (default) or Polar coordinates by clicking the or icons. A radiation pattern in Cartesian coordinates is shown in Figure 7.16, and the pattern in Polar coordinates is shown in Figure 7.19.

To compare radiation patterns in the same project, click the clone graph icon ; to compare radiation patterns from different projects, click the add graphs icon and select the desired graphs to add. Note that, in HOBBIES, the .ra1 files record the radiation pattern information, which is within the “POST” folder under the Project folder. So when the user is asked to add graphs, it is to select the desired .ra1 file for comparison. To delete a cloned or added graph, click the delete icon after switching to that graph tab. If the Group Mode check box is selected, the same group of results for all graphs will be displayed and all the manipulations done with one of the graphs will affect all graphs. For example, click the icon twice and two graphs are cloned and added to the post-processinging window (graphs 2 and 3). Select the second and third frequency samples in the corresponding Freq. lists for graphs 2 and 3, respectively. The overlaid results are shown in Figure 7.20.

Figure 7.19. A 2D radiation pattern in Polar coordinates.

Figure 7.20. Clone two graphs to compare data.

Each curve is set with a unique color automatically. Users can modify the settings of each graph in the corresponding Options tab, which will be described in the Options tab section.

If the simulation is run in the Scatterer Modes, the excitations are plane waves. The Excit. drop-down list is shown in Figure 7.21 (a). In addition, two quantities in the Quantity box are different from those in Antenna Modes, which are described as follows {Figure 7.21 (b)}:

• RCS: radar cross section normalized to λ² for scatterers (default)
• RCS (dB): radar cross section in dB for scatterers

Other options in Scatterer Modes are the same as those in Figure 7.17.

Figure 7.21. In Scatterer Modes: (a) Excitation drop-down list, (b) Quantity box.

• Options Tab in the Left Panel

Click on Options to display the Options tab, as shown in Figure 7.22.

To edit the title of the legend, deselect the Automatic Title check box, click on the Modify Title in the Title edit field, and then the Enter title window appears, as shown in Figure 7.23. For example, the default title is “E-theta - Gain(dB) > Gen. no. 1 300.000 MHz Phi= 0.000”. However, the user can change the title at will. Click Ok and the title of the legend changes accordingly.

To change the color of the plot, click on the Color field and the Select color window appears, as shown in Figure 7.24. By default the color is blue. Select the desired color, and click OK. A color setting example for radiation pattern is shown in Figure 7.25.

To change the plot style, click on the Style field, and select the desired style in the drop-down list. There are two styles available: Line/Dot and Line, as shown in Figure 7.26 (a). The default plot style is Line/Dot.

To change the line pattern, click on the Pattern field, and select the desired pattern in the drop-down list. The pattern types are shown in Figure 7.26 (b). The default line pattern is a solid line.

Figure 7.22. Options tab in the Left Panel with notations for 2D radiation patterns.

Figure 7.23. Enter title window.

Figure 7.24. Select color window.

Figure 7.25. Color setting for radiation pattern: (a) the default blue color, (b) the selected red color.

Figure 7.26. Drop-down lists: (a) Style list, (b) Pattern list.

To change the line width, click the increase/decrease icon in the Line-Width field. The default width is 1.

To change the dot size, click the increase/decrease icon in the Point-Size field. The default size is 5.

To enable or disable the grid in a 2D graph, select or deselect the Grid check box. By default, the grid is enabled as shown in Figure 7.25. As a comparison, Figure 7.27 shows the graph without a grid.

Figure 7.27. A 2D graph without a grid.

To set the x/y-axis label in Cartesian coordinates, click on Modify Label in the X/Y-axis field and an Enter value window appears. Enter the label name and click OK. For example, enter Theta [deg] for the x-axis and Gain [dB] for the y-axis, respectively, as shown in Figure 7.28. The graph with new labels is shown in Figure 7.29.

Figure 7.28. Enter value windows for (a) x-axis label, (b) y-axis label.

Figure 7.29. New labels for x-axis and y-axis.

• Range Tab in the Left Panel

Click on Range to display the Range tab, as shown in Figure 7.30. The default ranges may not display the graph in enough detail, so users can set up the suitable Maximum, Minimum, and Resolution values in the corresponding fields in the Angle Range and Radiation Pattern Range boxes. Press Enter and the ranges will be changed accordingly.

The increment for the range is calculated through the following equation:

Select the Fix Range check box and the current ranges will be applied to all results that are selected in the Data tab. Note that results added after the range has been fixed will also be displayed with the new fixed range assignments. To change the ranges back to default, click the Reset Range button.

For example, the default ranges for a 2D radiation pattern are shown in Figure 7.30, and the new ranges are set as those in Figure 7.31. The corresponding plots are demonstrated in Figure 7.32.

• Options in the Mouse Menu

The options in the mouse menu are shown in Section 7.2.4.

When viewing a 2D radiation pattern in Cartesian coordinates, click the LabelSelect option in the mouse menu and then select the data points to view the values. Press Esc and the (x, y) values are displayed, as shown in Figure 7.33. To view the values of all data points, use the LabelAll in option.

Figure 7.30. Range tab in the Left Panel with notations for 2D radiation patterns.

Figure 7.31. Set ranges for a 2D radiation pattern.

The graph can be copied and pasted into a file, such as a Microsoft Office Word document, by using Image to Clipboard in the mouse menu. Also the graph can be zoomed or panned by using the zoom or pan icon to size the graph appropriately so that the title does not infringe on the actual plot.

• Exporting Results to A Graph File

To export radiation pattern results to a graph file and to plot it with other tools (e.g. Matlab of Mathworks, Natick, MA and OriginLab Data Analysis and Graphing Software), click the FilesExportGraph menu, select the radiation pattern, and then a dialog box appears, as shown in Figure 7.34. Enter a file name and choose the directory in which to save the graph file.

Figure 7.32. Plots with different ranges: (a) the default range, (b) the new range.

Figure 7.33. A 2D radiation pattern with five marked data points.

Figure 7.34. Save graph files dialog box.

7.3.2.2 3D Radiation or Scattering Patterns

Menu: HOBBIES ResultsRadiation (3D) for Antenna Modes

Menu: HOBBIES ResultsScattering (3D) for Scatterer Modes

Toolbar:

Starting with a project that utilizes Antenna Modes as an example, click the Radiation (3D) option in the HOBBIES Results drop-down menu and a 3D radiation pattern is shown, as depicted in Figure 7.35. The Left Panel contains three tabs: Data, Options, and Range, which will be described next.

• Data Tab in the Left Panel

The Data tab for 3D radiation patterns is shown in Figure 7.36. The functionality is same as that for 2D radiation patterns, as described in Section 7.3.2.1.

• Options Tab in the Left Panel

Click on Options to display the Options tab, as shown in Figure 7.37.

In the Pattern Properties box, users can set several properties for patterns. To change the pattern style, click the Style field and select the desired style in the drop-down list. There are nine styles in the list (Figure 7.38), which are the same as those in Figure 7.15. The default style is . To make the pattern transparent, click the icon in the Transparent field and the icon becomes . Click it again to change the pattern back to the default opaque mode. The dB-Range option is valid for Gain (dB) in the Data tab, and users can enter a number in the dB-Range field to change the range of pattern. The default dB-Range is 50 dB. To change the pattern scale versus the structure dimension, enter a value in the Scale factor field and press Enter. The default factor is 1.

Figure 7.35. A 3D radiation pattern with the Left Panel.

Figure 7.36. Data tab in the Left Panel for 3D radiation patterns.

The default location of the 3D pattern is at the origin (i.e., (0, 0, 0)). In the Pattern Location box, the user can edit the X/Y/Z-coordinates of the pattern and then the pattern will be moved to the location set by the user. In some cases, for example, if an antenna is not at the origin, the pattern can be moved to the antenna location through this option.

Figure 7.37. Options tab in the Left Panel with notations for 3D radiation patterns.

The simulated model is displayed together with the 3D radiation pattern by default. The model can be shown in different styles, which are the same as those described in Section 7.3.1. To change the style, click the Style field in the Structure Properties box and select one style in the drop-down list (Figure 7.38). The default style is . To hide the model, deselect the Display check box.

The legend of the 3D radiation pattern is displayed by default. To hide the legend or the legend border, deselect the Display or Border check box in the Legend Properties box. To change the legend background to be transparent, deselect the Opaque check box. To change the color bar of the legend, click the Colors field and select one color bar in the drop-down list, as shown in Figure 7.39.

To view normalized 3D radiation patterns, select the Normalize check box in the Normalized pattern box.

Figure 7.38 Style drop-down list.

Figure 7.39 Colors drop-down list.

• Range Tab in the Left Panel

Click on Range to display the Range tab, as shown in Figure 7.40. The default ranges for 3D radiation patterns may not display the pattern in enough detail, so users can set up the suitable Maximum, Minimum, and Resolution values in the Radiation Pattern Range box. Press the Enter key and the ranges will be changed accordingly. Note that the number of colors in the color bar is equal to the Resolution value.

In the Minimum/Maximum Out Limits Color box, the color of the radiation pattern values beyond the minimum/maximum limit in the Radiation Pattern Range box are set as the minimum/maximum value color by default. The color can be also set to Black/White/Transparent.

Check the Fix Range box and the current ranges will be applied to all results selected in the Data tab. To change the ranges back to default, click the Reset Range button.

Note: The dB-Range in the Options tab can also be used to set 3D radiation pattern ranges. The dB-Range option works only if its value is less than the radiation pattern range (i.e., the difference between the Maximum value and the Minimum value in the Radiation Pattern Range box).

For example, the default range and color for the minimum/maximum outer limit of a 3D radiation pattern (Gain in dB) is shown in Figure 7.40. The new range is set as in Figure 7.41, and White is selected in both the Minimum and Maximum Out Limits Color boxes. The corresponding plots are demonstrated in Figure 7.42, along with a radiation pattern whose pattern range is set by the dB-Range option in the Options tab.

Figure 7.40. Range tab in the Left Panel with notations for 3D radiation patterns.

Figure 7.41. Set range for a 3D radiation pattern.

Figure 7.42. Plots with different ranges: (a) the default range, (b) the range set in Figure 7.41, (c) the range set by 20 dB in the dB-Range field of the Options tab.

• Options in the Mouse menu

The options in the mouse menu are shown in Section 7.2.4. When viewing a 3D radiation pattern, click the LabelSelect option in the mouse menu and then select the data points to view the values. Press Esc and the values are displayed, as shown in Figure 7.43. To view the values of all data points, use the LabelAll in option. The graph can be copied and pasted into a file, such as a Microsoft Office Word document, by using Image to Clipboard in the mouse menu.

Figure 7.43. A 3D radiation pattern with three data points marked.

7.3.2.3 2D Radiation or Scattering Patterns over a Frequency Band

Menu: HOBBIES ResultsRadiation (2D-Freq) for Antenna Modes.

Menu: HOBBIES ResultsScattering (2D-Freq) for Scatterer Modes.

Toolbar:

Starting with a project that utilizes the Antenna Modes as an example, click the Radiation (2D-Freq) option in the HOBBIES Results drop-down menu and a 2D radiation pattern is shown, as depicted in Figure 7.44. The Left Panel contains three tabs: Data, Options, and Range. The tabs for 2D radiation patterns over a frequency band, as well as for other options (e.g., options in the mouse menu), are similar to those for 2D radiation patterns described in Section 7.3.2.1.

7.3.3 Viewing the Y, Z, S Parameters

Menu: HOBBIES ResultsY, Z, S Parameters for Antenna Modes

Toolbar:

Y, Z, S Parameters are available for Antenna Modes. Click the Y, Z, S Parameters option on the HOBBIES Results drop-down menu and a 2D plot is shown, as depicted in Figure 7.45. The Left Panel contains three tabs: Data, Options, and Range, which will be described next.

Figure 7.44. A radiation pattern over a frequency band with the Left Panel.

Figure 7.45. Y, Z, S parameters with the Left Panel.

• Data Tab in the Left Panel

The Data tab is the default tab in the Left Panel, which contains the network parameters to be displayed. The Data tab with notations is shown in Figure 7.46.

In the Parameters box, there are three types of network parameters:

• Y (Admit.): Y-parameters (Admittance)
• Z (Imped.): Z-parameters (Impedance)
• S (Scat.): S-parameters (Scattering)

Note that S (Scat.-dB) denotes dB values for the magnitude of S-parameters. The default parameters are S (Scat.) parameters.

The Quantity box displays different quantities for the network parameters:

• Real: real part of the network parameters
• Imag.: imaginary part of the network parameters
• Mag.: magnitude of the network parameters (default)
• Phase: phase of the network parameters

Figure 7.46. Data tab in the Left Panel with notations for Y, Z, S parameters.

In the Ports box, one Input-port (j) and one Output-port (i) have to be selected in corresponding drop-down lists to view the network parameters. Alternatively, click the shortcuts and to change the output-port and click the shortcuts and to change the input-port. By default, both the input and output-ports are the first port. The functionality of other options in Figure 7.46 is the same as those in Figure 7.17.

• Options and Range Tabs in the Left Panel

The Options and Range tabs for Y, Z, S parameters are shown in Figure 7.47. The functionality in these tabs is the same as those for 2D radiation patterns (Section 7.3.2.1). Other options, such as the options in the mouse menu, are also similar.

Figure 7.47. Tabs in the Left Panel for Y, Z, S parameters: (a) Options tab, (b) Range tab.

7.3.4 Viewing the Near-Field

7.3.4.1 2D Near-Field Distribution

Menu: HOBBIES ResultsNear-field (2D)

Toolbar:

Starting with a project that utilizes the Antenna Modes as an example, click the Near-field (2D) option in the HOBBIES Results drop-down menu and a 2D near-field plot is shown, as depicted in Figure 7.48. The Left Panel contains three tabs: Data, Options, and Range, which will be described next.

Figure 7.48. A 2D near-field plot with the Left Panel.

• Data Tab in the Left Panel

The Data tab is the default tab in the Left Panel, which contains 2D near-field results to be displayed. The Data tab with notations is shown in Figure 7.49.

The Freq. and the Excit. drop-down lists are just the same as that in the data tab for the 2D Radiation option (refer to Section 7.3.2.1).

In the Component box, users can select the vector component to be displayed:

• E: total electric field (default)
• Ex: x-component of the electric field vector
• Ey: y-component of the electric field vector
• Ez: z-component of the electric field vector
• H: total magnetic field
• Hx: x-component of the magnetic field vector
• Hy: y-component of the magnetic field vector
• Hz: z-component of the magnetic field vector
• P: total Poynting vector
• Px: x-component of the Poynting vector
• Py: y-component of the Poynting vector
• Pz: z-component of the Poynting vector

In the Quantity box, users can choose the quantity in which the selected vector component is displayed:

• Real: real part of the vector component
• Imaginary: imaginary part of the vector component
• Magnitude: magnitude of the vector component
• Phase: phase of the vector component

Figure 7.49. Data tab in the Left Panel with notations for 2D near-field.

In the Independent Variable box, users can choose the plane in which to display the near-field:

• XoY: to display the near-field versus the z-coordinate for the selected x- and y-coordinate.
• XoZ: to display the near-field versus the y-coordinate for the selected x- and z-coordinate.
• YoZ: to display the near-field versus the x-coordinate for the selected y- and z-coordinate.

To change the coordinate when a plane is selected, click the X, Y, or Z-coord field and choose one coordinate in the drop-down list. Alternatively, the shortcuts , , , , , may be used.

The functionality of the other options in Figure 7.49 is the same as those in Figure 7.17.

• Options and Range Tabs in the Left Panel

The Options and Range tabs for 2D near-fields are shown in Figure 7.50. The functionality is the same as those for 2D radiation patterns (Section 7.3.2.1) and other options such as the options in the mouse menu are similar.

Figure 7.50. Tabs in the Left Panel for near-field (2D): (a) Options tab, (b) Range tab.

7.3.4.2 3D Near-Field Distribution

Menu: HOBBIES ResultsNear-field (3D)

Toolbar:

Starting with a project that utilizes the Antenna Modes as an example, click the Near-field (3D) option in the HOBBIES Results drop-down menu and a 3D near-field plot is shown, as depicted in Figure 7.51. The Left Panel contains four tabs: Data, Options, Range, and Cuts, which will be described next.

Figure 7.51. A 3D near-field plot with the Left Panel.

• Data Tab in the Left Panel

The Data tab is the default tab in the Left Panel, which contains 3D near-field results to be displayed, as depicted in Figure 7.52. The Data tab for Near-field (3D) is similar to that for Near-field (2D), as described in Section 7.3.4.1.

Figure 7.52. Data tab in the Left Panel for the 3D near-field.

• Options Tab in the Left Panel

Click on Options to display the Options tab, as shown in Figure 7.53.

The Structure Properties and Legend Properties boxes are the same as those in the Options tab for 3D radiation/scattering patterns described in Section 7.3.2.2.

In the Animation box, users can select the vector component to view the animated change in the time domain, assuming time harmonic excitation:

• E(t): total electric field (default)
• Ex(t): x-component of the electric field vector
• Ey(t): y-component of the electric field vector
• Ez(t): z-component of the electric field vector
• H(t): total magnetic field
• Hx(t): x-component of the magnetic field vector
• Hy(t): y-component of the magnetic field vector
• Hz(t): z-component of the magnetic field vector
• P(t): total Poynting field
• Px(t): x-component of the Poynting vector
• Py(t): y-component of the Poynting vector
• Pz(t): z-component of the Poynting vector

Figure 7.53. Options tab in the Left Panel with notations for the 3D near-field.

By selecting the Display vectors check box, the arrows will be displayed for vector fields, as shown in Figure 7.54.

Figure 7.54. The 3D near-field animation: (a) with vectors, (b) without vectors.

Enter the number of steps and total time in the Steps and Total time edit fields. The default values are 1 and 5 seconds, respectively. Users can choose to:

• : rewind the animation
• : stop the animation
• : play the animation
• : skip forward to the end of the animation

The slider shows the process of animation. The ω t field shows the instantaneous phase between 0° and 360°. If users want to view the endless animation, select the Endless check box.

The animation of near-fields can be saved as a video file in different formats and with different resolutions by completing the following steps:

1. Choose the desired options in the video format and video resolution drop-down lists (Figure 7.55). The default format is MPEG.

   

   Figure 7.55. Video drop-down lists: (a) video formats, (b) video resolutions.

2. Select the Save check box in Figure 7.53.
3. Click the play button , and a dialog box appears (Figure 7.56). Enter a name for the video file, and select a directory in which to save it. The file will be created until the animation is finished. Note that the endless animation cannot be saved because of the limited hard disk space.

Figure 7.56. Save animation video dialog box.

• Range Tab in the Left Panel

Click on Range to display the Range tab, as shown in Figure 7.57.

The Range tab for the 3D near-field is similar to that for 3D radiation or scattering patterns, as described in Section 7.3.2.2.

Figure 7.57. Range tab in the Left Panel for the 3D near-field.

• Cuts Tab in the Left Panel

Click on Cuts and the Cuts tab is displayed, as shown in Figure 7.58, which includes the x-cut, y-cut and z-cut tabs. To display the desired near-field cuts, select the check boxes before the cuts in the Cut list of the x/y/z-tab. The default cut displayed is the first z-cut.

For example, one x-cut, one y-cut, and one z-cut are selected in Figure 7.59. Figure 7.60 displays the near-field distribution on those three cuts. Users can select more cuts to view the 3D near-field.

To change the near-field distribution from the Opaque mode (default) to the Transparent mode, click the icon in the Trans list. The icon (Opaque) changes to (Transparent). Click it again and the near-field distribution is changed back to the Opaque mode. The near-field distribution in the Transparent mode is shown in Figure 7.61.

While viewing the 3D near-field, users can choose different styles to display them. Click the icon in the Style column, there are several styles available in the drop-down list, which are similar to those for 3D radiation or scattering patterns described in Section 7.3.2.2.

The screenshots of 3D near-field distributions can be exported to files of several different types: EPS, BMP, GIF, JEPG, PNG, and TIFF, as shown in Figure 7.58. To export a screenshot, click one of the six icons in Figure 7.58. A dialog box will appear (Figure 7.62). Enter a file name, select a directory, and click Save to create a screenshot file.

• Options in the Mouse menu

The options in the mouse menu are shown in Section 7.2.4.

When viewing 3D near-field distributions, click the LabelSelect option in the mouse menu and then select the desired data points to view the values. Press Esc and the values are displayed, as shown in Figure 7.63. To view the values of all data points, use the LabelAll in option.

The graph can be copied and pasted into a file, such as a Microsoft Office Word document, by using Image to Clipboard in the mouse menu.

Figure 7.58. Cuts tab for the 3D near-field.

Figure 7.59. Selection of three cuts.

Figure 7.60. Near-field distribution on the three cuts.

Figure 7.61. Near-field distribution in the Transparent mode.

Figure 7.62. Dialog box for saving a screenshot.

Figure 7.63. 3D near-field distribution with three marked data points.

7.3.5 Viewing the Electric or Magnetic Current

Menu: HOBBIES ResultsElectric/Magnetic current

Toolbar:

Click the Electric current option in the HOBBIES Results drop-down menu and the electric current distribution is shown, as depicted in Figure 7.64. The Left Panel contains three tabs: Data, Options, and Range, which will be described next.

• Data Tab in the Left Panel

The Data tab is the default tab in the Left Panel, which contains electric current results to be displayed. The Data tab with notations is shown in Figure 7.65.

Figure 7.64. Electric current distribution with the Left Panel.

In the Component box, users can select the current component to be displayed:

• J: total electric current (default)
• Jp: p-component of the electric current
• Js: s-component of the electric current

In the Quantity box, users can choose the quantity in which the selected current component will be displayed:

• Real: real part of the current component
• Imaginary: imaginary part of the current component
• Magnitude: magnitude of the current component (default)
• Phase: phase of the current component
• Mag. (dB): magnitude of the current component in dB

The functionality of other options in Figure 7.65 is the same as those in Figure 7.17.

• Options and Range Tabs in the Left Panel

The Options and Range tabs for electric current distributions are shown in Figure 7.66. The functionality is similar to those for 3D near-field distributions, as described in Section 7.3.4.2.

• Options in the Mouse menu

The options in the mouse menu are shown in Section 7.2.4.

When viewing electric currents, click the LabelSelect option in the mouse menu and then select the desired data points to view the values. Press Esc and the values are displayed, as shown in Figure 7.67. To view the values of all data points, use the LabelAll in option.

The graph can be copied and pasted into a file, such as a Microsoft Office Word document, by using Image to Clipboard in the mouse menu.

Figure 7.65. Data tab in the Left Panel with notations for electric currents.

Figure 7.66. Tabs in the Left Panel for electric currents: (a) Options tab, (b) Range tab.

Figure 7.67. Electric current distribution with three marked data points.

The functionality of the Data, Options, and Range tabs for the Magnetic current is the same as that of the tabs for the Electric current. Note that magnetic currents exist on surfaces of dielectric structures.

7.4 LEAVING POST-PROCESSING WINDOW

Menu: FilesPreprocess

Toolbar:

Select the FilesPreprocess menu or click the icon on the Toolbar. This option switches the window from the post-processing window back to the HOBBIES preprocess window.

7.5 LIMITATION OF POST-PROCESSING DISPLAY IN ACADEMIC VERSION OF HOBBIES

For the academic version of HOBBIES, this license only allows 3000 nodes for the mesh and 5000 sampling points for the post-processing display, as also presented in details in Section 6.9.3.

7.6 CONCLUSION

The post-processing window containing the Top menu, Toolbar, Left Panel, Mouse menu, and Command Line is introduced in this chapter. Furthermore, the plot of the HOBBIES output results including 2D/3D radiation and scattering patterns, Y/Z/S parameters, 2D/3D near-fields, and electric/magnetic currents is also described in detail.