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huiyuzz
Joined: 22 Jul 2004
Posts: 46
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 12 Aug 2004 10:59 Extended Inner Conductor Antenna Simulation in HFSS |
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Hi,
I'm trying to simulate a type of coaxial antenna as attached. The outer conductor is stripped off at one section, exposing the dielectric. And the inner conductor is extended.
This design is suppose to give a far-field radiation pattern similar to a half-wave dipole. However I tried modeling it in HFSS, I kept getting 4 lobes, instead of the desired 2 for the radiation pattern, and the S11 is horrible.
CAn anyone advise me where are my mistakes? Thankz!
Cheers
huiyuzz
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huiyuzz
Joined: 22 Jul 2004
Posts: 46
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| 19 Aug 2004 3:26 Re: Extended Inner Conductor Antenna Simulation in HFSS |
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HI,
regarding this project, I think i've got my excitations wrong as I cannot even obtain any e-ield radiation. I'm confused with the port assignment. How many wave ports shld i use? where and what size according to the Figure?
Cheers
huiyuzz
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wlcsp
Joined: 16 Aug 2004
Posts: 175
Helped: 14
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| 19 Aug 2004 15:32 Re: Extended Inner Conductor Antenna Simulation in HFSS |
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Please try the attached file and let me know the result.
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huiyuzz
Joined: 22 Jul 2004
Posts: 46
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| 20 Aug 2004 11:35 Re: Extended Inner Conductor Antenna Simulation in HFSS |
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Oops,
Thanx for the help: wlcsp. tried tat. Gives a less than -10dB S11..
Hmmm.... cud it be my model is wrong (wrond interpretation of the figure), not with the excitatation?
Puzzled....
huiyuzz
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wlcsp
Joined: 16 Aug 2004
Posts: 175
Helped: 14
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| 20 Aug 2004 12:04 Re: Extended Inner Conductor Antenna Simulation in HFSS |
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What the about the radiation pattern. Is it as you expect ?
Do you have any measurement data you can compare with?
Using air as dielectric is a bit strange.
Is that figure the only information you got about the structure?
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limate
Joined: 04 Jun 2004
Posts: 26
Helped: 1
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| 23 Aug 2004 0:08 Re: Extended Inner Conductor Antenna Simulation in HFSS |
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| I think there is something incorrect for your port definition.
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huiyuzz
Joined: 22 Jul 2004
Posts: 46
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| 23 Aug 2004 2:21 Re: Extended Inner Conductor Antenna Simulation in HFSS |
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I'm onli using a waveport that covers the cross-section of the dielectric and inner conductor. Tried to define integration line from inner conductor to outer conductor and vice versa, doesnt seemed to make a diff.
My solution type is "Driven Modal".
Hmmm..... I just know my model is wrong, but dunno where is the prob.. been trying to trial and error to find where went wrong..
huiyuzz
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huiyuzz
Joined: 22 Jul 2004
Posts: 46
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| 15 Sep 2004 10:14 Re: Extended Inner Conductor Antenna Simulation in HFSS |
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After struggling for 1 month, I still cannot get the right results. One evidence to prove my simulations wrong is the E-filed intensity plot.
Attached is the plot given in the paper. And the one I've got.
*scratch head*
Where could went wrong?
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asdfaaa
Joined: 31 Aug 2004
Posts: 235
Helped: 42
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| 18 Sep 2004 11:47 Re: Extended Inner Conductor Antenna Simulation in HFSS |
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| wlcsp wrote: |
| Please try the attached file and let me know the result. |
hi,wlcsp, I dont understand why you can add the pec cap there, I thought you spoiled the wave port on that plane.
Best regards,
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