Coaxial Loop Antenna (coaxialLoopAntenna.sdf)


coaxial, coaxial waveguide, coaxial cable

Problem description

This example illustrates how to use the coaxial cable Field Boundary Condition and Constructive Solid Geometry to create a coaxial loop antenna.

This simulation can be run with a VSimEM, VSimMD, VSimPD, or VSimPA license.

Opening the Simulation

The Coaxial Loop Antenna example is accessed from within VSimComposer by the following actions:

  • Select the NewFrom Example… menu item in the File menu.
  • In the resulting Examples window expand the VSim for Electromagnetics option.
  • Expand the Antennas option.
  • Select “A Loop Antenna created from a coaxial cable” and press the Choose button.
  • In the resulting dialog, create a New Folder if desired, and press the Save button to create a copy of this example.

The Setup Window is shown Fig. 175.

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Fig. 175 Setup Window for the Coaxial Loop Antenna example.

Simulation Properties

This simulation makes use of the new coaxial waveguide Field Boundary Condition in VSim 8.1.

A coaxial waveguide is first constructed by creating a physical coaxial cable that enters the simulation domain. It is very important that this cable exist from atleast 1 cell outside of to 1 cell inside the simulation boundary. This is done by first creating a box primitive and setting it along the desired simulation boundary.

A cylinder corresponding to the outer diameter of the coaxial cable is then created, and subtracted from the plate.

A cylinder corresponding to the inner diameter of the coaxial cable is then created and extended into the simulation space.

It is then made into a loop antenna by adding a second, intersecting cylinder.

The wave itself is specified by a Field Boundary Condition.

Running the Simulation

Once finished with the problem setup, continue as follows:

  • Proceed to the Run Window by pressing the Run button in the left column of buttons.
  • Choose parallel computing options on the MPI tab
  • To run the file, click on the Run button in the upper left corner of the Logs and Output Files pane. You will see the output of the run in this pane. The run has completed when you see the output, “Engine completed successfully.”
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Fig. 176 The Run Window at the end of execution.

Visualizing the Results

Under Scalar Data select E_z. To slice inside the field, select Clip All Plots in the lower left hand corner. Click on Plane Controls and change the cut-plane normal to lie along Y instead of Z, and adjust the origin of the normal vector to .05 . Under the colors button set the min to -10 and the max to 10 to see the field.

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Fig. 177 The \(E_{z}\) field propagating off of the loop antenna.

Further Experiments