You couple two or more sources using the '''Port Definition Dialog'''. To do so, you need to change the default port assignments. First, delete all the ports that are to be coupled from the Port List of the dialog. Then, define a new port by clicking the '''Add''' button of the dialog. This opens up the Add Port dialog, which consists of two tables: '''Available''' sources on the left and '''Associated''' sources on the right. A right arrow ('''-->''') button and a left arrow ('''<--''') button let you move the sources freely between these two tables. You will see in the "Available" table a list of all the sources that you deleted earlier. You may even see more available sources. Select all the sources that you want to couple and move them to the "Associated" table on the right. You can make multiple selections using the keyboard's '''Shift''' and '''Ctrl''' keys. Closing the Add Port dialog returns you to the Port Definition dialog, where you will now see the names of all the coupled sources next to the name of the newly added port.
{{Note|It is your responsibility to set up coupled ports and coupled [[Transmission Lines|[[Transmission Lines|[[Transmission Lines|[[Transmission Lines|[[Transmission Lines|[[Transmission Lines|[[Transmission Lines|[[Transmission Lines|[[Transmission Lines|[[Transmission Lines|[[Transmission Lines|[[Transmission Lines|[[Transmission Lines|transmission lines]]]]]]]]]]]]]]]]]]]]]]]]]] properly. For example, to excite the desirable odd mode of a coplanar waveguide (CPW), you need to create two rectangular slots parallel to and aligned with each other and place two gap sources on them with the same offsets and opposite polarities. To excite the even mode of the CPW, you use the same polarity for the two collocated gap sources. Whether you define a coupled port for the CPW or not, the right definition of sources will excite the proper mode. The couple ports are needed only for correct calculation of the port characteristics.}}
[[File:PMOM51(2).png|800px]]
Figure 2: An example of the 3D mono-static radar cross section plot of a patch antenna.
Â
=== Viewing & Visualizing Various Output Data Types ===
Â
At the end of a planar MoM simulation, a variety of 2D and 3D output data are generated. Some of these can be visualized or graphed directly from the Navigation Tree, while the others can only be accessed from the Data Manager. All of [[EM.Cube]]'s simulation data are always written into ASCII data files that you can open and inspect or edit. Lists of these 2D and 3D data files appear under Data Manager's various tabs. The generated data also include all of [[Planar Module]]'s legitimate standard outputs that the simulation engine can compute given the specified source and observable types as well as all of your own previously defined custom output [[parameters]]. Note that in this release of [[EM.Cube]], all the custom outputs are real-type data. Each custom output is written into a separate real data file with the same name as the parameter's given label and a "'''.DAT'''" file extension. To open data manager, click the '''Data Manager''' [[File:data_manager_icon.png]] button of the '''Simulate Toolbar''' or select '''Simulate > Data Manager''' from the menu bar, or right click on the '''Data Manager''' item of the Navigation Tree and select '''Open Data Manager'''... from the contextual menu. You can also use the keyboard shortcut '''Ctrl+D''' at any time. Select any data file by clicking and highlighting its row in the table and then click the '''Plot''' button to plot its graph in '''EM.Grid'''. You can also view the contents of a data file by selecting its row in th file list and clicking the '''View''' button of the dialog or by simply double-clicking the highlighted row. This opens up a new window containing a convenient spreadsheet that gives a tabular view of the contents of the selected data file. There are a large number of data operations and manipulations that you can perform on the data content including matrix, calculus and statistical calculations as well as computing and plotting new datasets using the "Compute" feature of the spreadsheet. You can make multiple file selection using the keyboard's '''Ctrl''' and '''Shift''' keys.
Â
[[File:PMOM144.png]]
Â
Figure 1: [[EM.Cube]]'s Data Manager dialog showing an angular file selected and highlighted for further action.
Â
[[File:PMOM143.png]]
Â
Figure 2: Data Manager's spreadsheet showing the contents of an angular data file.
Â
The 2D output data include real or complex quantities like various port, radiation, scattering and periodic characteristics. At the end of an analysis, most .CPX and .DAT data files have a single complex or real value, respectively. in other words, there are no curves to plot. Exceptions are Cartesian 2D radiation pattern or RCS data files along the principal and user define phi-cut planes, as well as polar 2D radiation pattern or RCS data files of angular type with a "'''.ANG'''" file extension. These files contain the radiation pattern or RCS data as a function of some relevant angle in the specified plane. At the end of a sweep simulation of one of the many types available (frequency, angular, parametric, etc.), the ASCII output data files are populated with rows that correspond to the samples of the sweep variable(s). You can plot graphs of the 2D output data files that contain more than one row in '''EM.Grid'''. Each data file has a default graph type. Real data are plotted on EM.Grid's Cartesian graphs. Complex data files with a "'''.CPX'''" extension are plotted on double Cartesian graphs of "'''Magnitude-Phase'''" type, showing the magnitude in dB and phase in radians. You can change the complex data's graph type to the "'''Real-Imaginary'''" or "'''Smith Chart'''" by selecting its entry in the Data Manager and clicking the '''Edit'''button to open the "Edit File Properties Dialog". Angular data files like polar 2D radiation patterns or RCS, by default, are plotted on EM.Grid's "'''Polar'''" graphs. Note that real data can be graphed on bar charts, too, just as angular can alternatively be graphed on polar stem charts.
Â
[[File:PMOM142.png|600px]]
Â
Figure: A 2D radiation pattern polar graph in EM.Grid.
Â
[[EM.Cube]]'s 3D output simulation data usually have a vectorial nature and are defined as functions of the Cartesian or spherical space coordinates. At the end of a planar MoM simulation, you can view 3D visualizations of the vectorial output data such as current distributions, near-field field distributions, far-field radiation patterns and RCS in [[EM.Cube]]'s project workspace by clicking on the corresponding observable entries in the Navigation Tree. When you run a sweep simulation of some sort, multiple 3D plots appear on the Navigation Tree representing all the sweep variable samples. You can animate these 3D visualization plots very conveniently from the Navigation Tree. To do so, right click on an observable's name in the Navigation Tree and select the '''[[Animation]]''' item from the contextual menu. Make sure that you right click on the observable's parent node, not on one of its child components corresponding to the sweep variable samples. The 3D plot in the project workspace starts to animate and continues forever until to stop it. A new window called "''' [[Animation]] Controls Dialog'''" opens up at the lower right corner of the [[EM.Cube]] desktop. This dialog allows you to control the [[animation]] speed using a box labeled '''Rate''', whose value multiplied by 100 milliseconds indeed gives the frame duration. You can speed up the [[animation]] or slow it down from the default rate of one frame per 300ms. The box labeled '''Sample''' show the current frame's plot label at any time. You can pause the [[animation]], rewind it to the first frame, fast-forward it to the last frame or manually step it through back and forth using the movement buttons marked with the symbols |<, <<, ||, >>,>|.
Â
[[File:PMOM135.png|600px]]
Â
Figure: Animating 3D radiation patterns as the send of a frequency sweep.
Â
[[File:PMOM136.png]]
Â
Figure: [[EM.Cube]]'s [[Animation]] Controls dialog.
== Periodic Planar Structures & Antenna Arrays ==