ANTENNA TESTING (Smith chart in Hfss)

Hello All,

I tested my antenna using VNA and got the S11. I then used the option of display to get the Smith chart , which has real and imaginary values.

How do I get the same smith chart (showing real and imaginary values of S11) in Hfss?


Or anyother way to get measured and simulated values of S11 in Smith Chart?

Thanks

Hi Mobinaz,

After simulating your model in HFSS you can see the smith chart as follows:


HFSS-->Results--->Creat Modal solution Data Report--> Smith chart

You will see the smith chart of your simulated model. To see the real and imaginary values, Just right click anywhere on the smithchart and select

Marker--> Add marker....

Click it on the point which you want to see in the form of Real and imaginary values. HFSS will show you the value in both polar form and cartesian form(R+jx)...Dont forget to multiply it by 50 Ohms as smith is normalized to 50 Ohms.

If you want to plot your simulated and measured smith chart together. Just Right click on the smith chart anywhere and then select Export, Export the data in any format you like (e.g csv etc) and then use another software like Matlab etc to plot both measured and simulated smith charts together for comparison.

I hope this is what you are asking for and it helps you somehow!

First of all thanks for replying.

I am using similar option for saving Smith chart from hfss, it saves freq vs S11
like these

Freq [GHz] S(LumpPort1,LumpPort1)

4.000000000000000 0.462092269044403
4.005000000000000 0.466968921928167
4.010000000000000 0.471837244795392
4.015000000000000 0.476696910722444

Now what I get from VNa are
real vs imaginary values.

How do I plot them both in MAtlab and inter relate.

Thanks

What I understand from your question is:
Using export option in HFSS, you are getting Freq in GHz and S11 in magnitude.
And from your network analyzer you are getting Freq and S11 (real) and S11 (imaginary), Is that right?

If I am correct, then do the following:
Since you are getting real and imaginary from the VNA, take the magnitude of the values. i.e sqrt(realvalue^2 + imagvalue^2).
The value should be more or less the same as that you got from HFSS.

For plotting in Matlab, export the excel sheet which has freq and the corresponding values of S11 in matlab and you can plot them.

If you are still having problems, upload the excel sheet. I think I can help you out.