Example 7: 16x16 Short Dipole Array with Binomial Algorithm
This case explains how to use the binomial algorithms to calculates the pointing parameters in a bidimensional short dipole array.
Step 1 Create a new MoM Project.
Open newFASANT and select File - New option.
Select MOM option on the previous figure and start to configure the project.
Step 2 Set the simulation parameters as shown.
Select Simulation - Parameters option, set the parameters and save it.
Step 3 Create the array.
Click on Source - Dipole - Dipole Array to create an array of 16x16 electrical short dipoles, with a spacing of 0.04 m, that are oriented following the y-axis. The array is located on the XY plane. The spacing of 0.04m is equivalent to a spacing of 0.267 in units of lambda, at a frequency of 2 GHz.
Step 4 Feed the array.
To set the feeding of the array select Source - Antenna Feeding and the following panel will open.
This is the default setting. To use the binomial algorithm click on Tools - User Function and select the corresponding function. NOTE: To use the bidimensional binomial function it is needed to download both the bidimensional and the unidimensional functions.
A path has been selected by default so the files will be created on the mydatafiles folder in the newFASANT directory.
The next step is generating the text file. To do so click on Tools - Calculator and write the call to the function.
- d1: element spacing of the array in the x axis in units of lambda
- N1: number of array elements of the array in the x axis
- d2: element spacing of the array in the y axis in units of lambda
- N2: number of array elements of the array in the y axis
- theta: beam angle, in degrees
- phi: azimuth angle, in degrees
In this case, set the parameters as shown. Angles of theta=45º and phi=0º are selected as an example.
Now, apply these results to the array created before by clicking on S ource - Antenna Feeding.
The panel shown before will appear. To use the weights and phases calculated with the binomial algorithm, click on Import.
Select the corresponding file and save the feeding.
Step 5 Create ground plane.
In order to avoid unwanted radiation to go below the array, create a ground plane using the plane command, or Geometry - Surface - Plane. The array is situated in the XY plane with z=0, so the z coordinate has to be negative.
View of the dipole array.
Step 6 Solver parameters.
Select Solver - Advanced Options and set the parameters as shown.
Step 7 Meshing the geometry model.
Select Mesh - Create Mesh to open the meshing configuration panel and then set the parameters as show the next figure.
Click on Mesh.
Step 8 Execute the simulation.
Select Calculate - Execute option to open simulation panel.
Step 9 Show Results.
The radiation cuts can be visualized by clicking on Show Results - Radiation Pattern - View Cuts.
The radiation pattern can be visualized by clicking on Show Results - Radiation Pattern - View 3D Pattern.