Learning Forum

[Hyliang69]

Hello everyone,

I am a new comer of Ansys Learning Forum.

Recently I am learning to get familiar with the HFSS software of Ansys.

I started with a very simple example, i.e., modelling a commonly used antenna radiator, which is a WR-90 waveguide (22.86mm*10.16mm) with one open end embedded in an infinite PEC ground to radiate energy into half free space. 

I completed the model, set the air box for radiation boundary and finished solution setup for analysis with the wave port excitation, the simulation process is all right, but the results seem very strange and obviously wrong, especially for the far field 3D pattern . 

I have attached with this question the .hfss file for this model, could anyone kindly help me to find out what are the mistakes?

In addition, I have another question concerning the coordinate system erected in HFSS modelling. In the model mentioned above, while I am defining the Perfect-E boundary condition for the rectangle within the infinite PEC ground plane, the default setting is to place the rectangle parallel to the plane z=0 (i.e., the x-o-y plane), in another word, the normal to the PEC ground plane is along the z-axis. However, what I intend to investigate most is the situation in which the PEC ground plane is placed at x=0 (i.e., the y-o-z plane) which comprises the open end of WR-90 waveguide (i.e., the radiator), thus the normal to this plane is along the x-axis.

Such a new definition of global Cartesian coordinate system, especially the new definition of z-axis direction, will inevitably affect the definitions of many variables in associated spherical coordinate system, not only the values and ranges of angle theta and angle phi, but also the directions of unit vectors theta and phi. Thus the far field calculations may exhibit different results, especially for polarimetric (dual-polarization) applications.

So, does anyone know how to solve this problem? Either by placing the PEC ground plane at x=0 in modelling process, or, by still placing the PEC ground plane parallel to plane

z=0 in modelling first, then finding desired dual-polarization results in the frame of new global Cartesian coordinate system in simulation or post-simulation process?

Many thanks for any answer or suggestion!

model.rar

[Praneeth]

Please provide snap shots of how you are defining the model as Ansys employees cannot access attachments across the forum.
Providing snap shots will help to understand your concern more effectively.
Regarding the second part of the question, you can use Relative co-ordinate system while defining your model.
All the very best.