Horn antenna with dielectric lens
The present example considers a rectangular waveguide horn antenna with lens.
Horn antenna with dielectric lens.
Horn antenna with dielectric lens project in QW-Modeller.
Length of the input waveguide of the antenna is 10 mm and its width and height are respectively 5 mm and 10 mm. The horn length is 20 mm and its width and height are respectively 15 and 20 mm. The thickness of the waveguide’s and horn’s thickness is 2 mm.
Inside the horn antenna two ridges are placed. The ridges are placed along the antenna height. the wisth and height of the ridge. In the horn section the ridges' height remains unchanged and the width expands to 3 mm. The ridges are placed along the antenna height.
The lens is made of teflon material (εr= 2.2) and its radius and thickness are respectively 15 mm and 7 mm.
For the purpose of calculating radiation patterns, the project contains NTF Box (green box), which is a virtual box determining the boundaries at which the near-to-far field transformation will be executed.
In case of radiating scenarios, the entire project should be terminated with absorbing boundary conditions conditions to model the free space surrounding. In this case we will use MUR absorbing boundary conditions in a form of MUR Box (blue box).
The transmission line input port is placed at the waveguide and it will excite the fundamental TE01 mode in the frequency range from 15 GHz to 25 GHz.
The S-Parameters postprocessing is set from 15 GHz to 25 GHz with the frequency step of 0.05 GHz.
The radiation pattern calculation is set at 20 GHz.
S-Parameters postprocessing and Near To Far postprocessing configuration dialogues.
Reflection coefficient of the horn antenna with lens.
We wish to calculate the 2D radiation patterns versus angle Theta varying between 0 and 180 degrees with a step of 2 degrees. They will be calculated with a constant angle Phi equal to 0 degrees. The definition of the angles is explained in the lower right part of the 2D Radiation Patterns configuration dialogue. Note that this definition depends on the choice of the reference axis. The angle Theta is always counted from the reference axis (X in the considered example). The angle Phi is always counted around it.
2D Radiation Patterns configuration dialogue.
The reference axis can be set to X, Y or Z by clicking respective radio buttons in the Axis column of the dialogue. There is also an option to define an arbitrary reference axis. For an example of application of this option, please refer to the Two dipoles in free space excited in phase.
We can set the reference point or in other words the origin of the coordinate system for the NTF transformation. The position of the reference point does not influence the absolute values of the radiation patterns (in lossless NTF background medium) but it does influence their phase characteristics. Moving the reference point can be helpful in a search for the antenna electrical centre. The reference point position is expressed in the same coordinates and units as those used in the project and defined in user input interface. To recall what units have been used, we can just take a look at the title bar of the window. In the considered example we see Units: mm.
2D radiation patterns calculated at 20 GHz.
2D radiation patterns in polar coordinates calculated at 20 GHz.
3D radiation pattern, with both Phi and Theta varying in steps can be calculated in the 3D Radiation Pattern window. The 3D Radiation Patterns dialogue allows setting the reference axis and steps for angles Phi and Theta, defined with respect to that axis in the same way as for the 2D radiation pattern case. A single frequency is also selected.
3D Radiation Patterns configuration dialogue.
3D radiation pattern calculated at 20 GHz.