CPW Feed squre Slot Antenna

[Faisel Tubbal]

Hi Guys

Can anyone help me out of this design,,,,
Actually, I am new user of HFSS and what I did is, I started building some exist designs so that I become familiar with this simulation. However, When I built the CPW Feed square Slot Antenna I got different results from the original one, so I think I have something wrong with the CPW feed as I got very high S11 which means most of the power is reflected.. I got same resonance frequency of the original 2.45GHz

The S11 that I got is -2 while the original one was about -18 which is good.

I appreciate your help.

 

[PlanarMetamaterials]

Can you attach the file or some plots?

 

[Faisel Tubbal]

Can you attach the file or some plots?

Thanks for your reply. I have attached the HFSS file (ZIP format)

kindly find the attached...

Best Regards

 

[Faisel Tubbal]

Hi

and This is the original results that I was aiming to achieve but as you can see in the previous hfss file results are completely different !!! I did something wrong,,,, maybe in the wave port feed part
could you please check it and advise me ?

regards

 

[PlanarMetamaterials]

Hi Faisel Tubbal,

You have some fairly fine features in your antenna, and no seed mesh. Additionally, you are using the default analysis setup with only 8 passes. This is a bad combination - you need to make sure that your simulation is well converged. I think you have two options:

1) Specify a seed mesh around the small gaps to ensure they are appropriately meshed
AND/OR
2) Increase maximum number of passes to at least 20 and specify a delta S of ~0.01

 

[Faisel Tubbal]

Hi Faisel Tubbal,

You have some fairly fine features in your antenna, and no seed mesh. Additionally, you are using the default analysis setup with only 8 passes. This is a bad combination - you need to make sure that your simulation is well converged. I think you have two options:

1) Specify a seed mesh around the small gaps to ensure they are appropriately meshed
AND/OR
2) Increase maximum number of passes to at least 20 and specify a delta S of ~0.01

Thanks mate for your reply >>

I have no idea about seed mesh. however, I have tried the second option by increasing the number of passes to 20 and making Delta S of 0.01 but there was no change in the results


Regards

 

[PlanarMetamaterials]

To get a seed mesh, place a vacuum object (or unassigned surface) wherever you have very small gaps in the PEC/copper. Then, right click on the object and select "Assign Mesh Operation". Select Length-based, and for the minimium mesh size choose the smallest feature size (pitch) of the gap. This will ensure that HFSS creates a reasonably fine mesh in this area.

 

[Faisel Tubbal]

I think there was a mistake in the designs. So instead of using ground plane at the top I have used a patch. so in the attached hfss file I have used ground plane at the very bottom and the top....

The results have been improved but still not like the original one .

if you can just have a look at the attached design and also I have attached the article that contain this design with all details.. I might used something wrong in the design or in hfss settings as I am very new user of HFSS...

thanks for your help