Please help with HFSS dipole antenna

[motorway]

Hello.
Can you please help with design of this antenna in HFSS 9.1 (see file). It works on frequencies about 1 Ghz. Which antennas like this are used by people? I need to get normal radiation pattern and S11 parameter. I use waveport. How can I optimize these parameters as function of antenna height? When I click project variables -> local there is some strangeness with units. And I get S11 ~= 0 db! It's wrong!
How antenna's screen actions upon radiation pattern? I don't want that antenna radiate downward.

I now don't remember my reg. number or something else, but please help, because my question is simple and small, and if I will not get answer I have to use another program.

Thanks. Ivan

 

[adel_48]

these antennas are generally used in cell phones (around 1GHz)

you need to send us the file, no file is attached to your message.

 

[motorway]

Please see this! How can I do normal antenna and where I can read about it? How screen is influences on pattern and S11? How I can see pattern vs different radiuses of screen?

 

[costox]

Hi motorway,

Have you found the answer yet ?
Please share with us your updated .hfss file (or you can send to my email
I think you should use project variable ($rd) instead of local variable (rd).
How? select in menu: project/project variable.

 

[heedavid]

Dear motorway,

I'd a quick scan through your structure, so I'll just give a few opinions.

Is that a monopole or a dipole you're simulating? Cos' the hf$$ structure looks like a quartered-up (you're making use of the image planes, right?) coax-fed monopole with curvy ground plain.

So, with respect to a pretty decent monopole simulation in HF$$, I think there are a few changes to be made:

(1) You don't have to use image-planes. It's a simple structure, you don't have to complicate your simulation results for that. Besides, I think you gotta do some post-processing (e.g. multiply the simulated impedance results for the final one) if you use the image-thingy.

(2) You don't have to have such a long coax-feed. Roughly the same height as your coax dielectric's diameter will do. This was suggested to me by HF$$ engineers.

(3) I think you need larger air-box/radiation boundaries. Your radiation boundaries should be at least 0.25 wavelengths (or more) to the tip(s) of your radiating element.

Hope these helps,
Dave