problem about computing antenna parameters
i am new here and also i have only recently started using HFSS. i am simulating microstrip patch antenna. f = 2.5GHz. S11 is quite well. At resonance frequency attenuation is about -10db.
However i can't compute antenna parameters like peak directivitiy, peak gain, max U. they are 0. i can't either plot radiation patern or directivity from "create far field report" after "insert far field setup" and create infinite sphere.
What could be problem?
Thank you in advance for your answers.
Yigit
Generally, you should be able to see the radiation pattern by plotting using "Create far field report" after "Creating the infinite sphere". I am not sure what's the problem with your HFSS .
Which version of HFSS are you using ?
Do you have an airbox/ radiation boundary?
Yes i have an airbox with quarter wave at 2.5GHz height and radiation boundry assign all faces of the airbox except bottom face of airbox.
I see only a blue sphere when i use "create far field report"
I am using HFSS 12.
Hello,
In project Manager windows, there is a yellow icon called Radiation. You must do: Insert a far field setup-> Infinite sphere. After you can create a far field report.
Ps : "At resonance frequency attenuation is about -10db" is not good and I think your antenna isn't correctly matched .
S.
Hello Stephens,
I know the yellow icon and i did the same things you said. However the result is same. I cant' see any antenna parameter.
Ps: I also know -10 db is not good but like i said i am new and i have recently started working on this issue. I am able to do just -10db. Can you give me some tips for fixing the matching problem.
By the way thank you for all the answers.
Yigit
Hi,
What kind of patch it is ?
Do you use microstrip line connected to your patch ?
Do you use microstrip line with coupling slot ?
Do you use coaxial connection ?
Do you have 50 ohms for your microstrip line or for you coaxial connection? (Zc on port excitation must be around 50 ohms for the solution frequency 2.5GHz)
What kind of port do you use ?
Lumped ? (for coaxial for example)
waveguide ? have you gave good dimensions to your port ? Can you see on port the fields ? Are they microstrip fields (Quasi-TEM).
(Not necessary : Have use "radiation boundary On ports")
If the microstrip line is directly connected to your patch you must put slots on patch to find 50 ohms like ../imgqa/eboard/Antenna/rf-2vekligqpgx.gif
Bye
S.