Serious losses in microstrip patch antenna HFSS

Hi everyone,
I am designing a microstrip patch antenna with coaxial feed and after a lot of troubleshooting i couldn't solve the fact that S11 parameter is very high!
Can anyone give me a hint on what should i look closely for reducing the incident losses?
Thanks

It might be the port you are feeding the patch with is very small. Check the dimensions of the wave port.

The port is equal to the outer conductor (teflon) diameter which is 1.675mm. How big should it be?

no it should be 10 times the radius of the inner in width and 10 times the distance between inner and outer in length.
Regards

Thanks for the response but what exactly do you mean the distance between inner and outer?

It would be the thickness of the teflon between the inner and the outer shield.

1. What's "very high" S11 for you?
2. How do you know that it's related to antenna (or feedline) losses? May be simply a mismatched antenna.
3. Sketching the geometry would help a lot.

Very high is any value greater than -30dB cause that means great mismatch. I am now posting the schematic.



New folder.rarNew folder.rar

but in patch antenna you wouldn't attain such value except at resonance.

I want to use it for 2.4 GHz for energy harvesting so at that frequency i want to have matching and resonance.

if the issue was not from the port dimension, then as FvM said your antenna would simply be unmatched.

Can you give us the value of the S11 and the value of the gain?
Or better, the screen shot with the results?

This is S11



Btw can anyone rerun the schematic to make sure that the data are correct? Because i had some problems in the past that gave me bad results and it came up that it had to do with the license of the software.
Thanks again

pal your antenna isn't matched. please try to sweep the length of the patch to attain better matching at that frequency.