bowtie antenna hfss simulation

Hi,

Can anyone please provide me with an example of bow-tie microstrip pacth antenna using HFSS. Any help would be appreciated.

Thanks

To chamonz,

I've written something about the bow-tie antennas in other threads, but I won't mind re-iterating myself again! ;)

After reading your post, I sorta understood what you're trying to say. So, we shall just constrain ourselves to a bow-tie DIPOLE etched on a substrate (hence, the 'patch' term you've used):

A bow-tie structure is inherently BROADBAND. To me, as long as anything that has a bandwidth of more than the conventional 10% - 15% (e.g. patch antenna) is broadband. But of course, if you're comparing to UWB antennas, definately it will seem 'narrowband' to you! ;)

So now considering a dipole structure over a ground plane, the usual lambda/4 objective still pertains. BUT, you can reduce that dipole-to-ground spacing with a suitable material. Now when that happens, the usual microstrip patch antenna analysis comes in. Of course, trade-offs also occurs, so you must be careful.

Now, on the other hand without proper design, when you place any scattering/radiating structure too close to the ground plane (e.g. in this case, maybe a commercially-off-the-shelf FR4 PCB thickness depth), you'll run the risk of 'shorting' it out. This could explain your "problem that the impedance, both real and imaginary, are almost zero". Your design probably shorted out certain modes of operation.

And for "about the space between two triangular patches", as long as it is no wider than lambda/4 to your designed half-wavelength bow-tie's fundamental operating frequency will do. Even having said that, I don't think there really is a 'specific' formula. And yes, I would recommend a parametric study on the spacing to see which suit you better. Would any readers care to comment?

I hope these helps,
Dave

To Dave..

THX 4 Ur answer.. Does it mean that I have to make the substrate thicker?? I'm so confuse.. This is a frequency independent antenna. So the frequency of this antenna will only depends on its angle.. So I think the length of the arm will not affect its frequency (PLZ give correction if what I think is wrong ). I have simulated many models and the results are still bad.. I have to make this antenna using FR4 coz in my country, the material available is only FR4-epoxy(εr=4.04 or 4.3) with different thickness started from 0.8mm, 1.5mm, 1.6mm, and 3.2mm.

About my antenna, if the bandwidth is only 80MHz and the centre frequency is 2.442GHz (for bluetooth application), don't you think it's kind of narrowband?? Bandwidth between VSWR 2:1 is quite wide, but I only use bandwidth 80MHz(VSWR 1.2:1). Will it still called Broadband antenna??

Another question.. I've read in another thread that when an antenna is work at high frequency (GHz or maybe more), the value of the imaginer part of the impedance will not affect the performance of the antenna.. Why??

THX again 4 Ur reply... :)

I just tripped over an example for a bow tie antenna in the version 10 user's guide for HFSS. See section 5.6. They based the example on Guiping, Zheng, et. al. "A coplanar waveguide bow-tie aperture antenna", Antennas and Propagation Society International symposium 2002. IEEE volume 1, 16-21 June 2002, pg. 564-567.

You can ask one of the application engineers for a copy.

(I only have paper.....)

I used this similar example but i am not getting the desired results..if at ease can i send you the hfss files?

Attach the hfss file here, so we can take a look at it.

here is an example file I just through together for you in HFSS. Hope this helps you let me know if it does.

The previous post has the results, I relized you may not want all the results just the example file so here it is.

This might also help you:

em: talk - Microstrip Patch Antenna Calculator

hanks for your kind consideration. Attached is the bowtie design. I am not getting correct S parameter plot shape. I have ap?ied lump feed as it is mentioned in the example but I am not clear about how it is implemented..i mean why not on y axis? thirdly I dont understand difference between `Driven Modal and Driven Terminal Terminal types.

Thanks again for your time.

Thanks I shall see it and contact you back..its indeed nice of you to help me out.

Regards.

---------- Post added at 23:46 ---------- Previous post was at 23:42 ----------

Thanks for your help. I shall see it and contact you back. Indeed kind of you to help me out

Regards.

Hi again. I was looking in to this example and interested to know that did u make the polylines out of a box..cuz i see thickness there. If that is so, then what thickness did you select? I would also like to know at which frequency is it designed for..so then according to the corresponding wavelength you must have selected the lengths.

Thanks,
Regards.

this post is old but if possible plz can u guide me for bow tie,i am trying to simulate cross bow tie antenna but its s para metesrs comes to be -.12 db onle and impedance is real part is zero and imginary part is 50 ohm,should i increase thickness of substrate?
QUOTE=heedavid;448467]To chamonz,

I've written something about the bow-tie antennas in other threads, but I won't mind re-iterating myself again! ;)

After reading your post, I sorta understood what you're trying to say. So, we shall just constrain ourselves to a bow-tie DIPOLE etched on a substrate (hence, the 'patch' term you've used):

A bow-tie structure is inherently BROADBAND. To me, as long as anything that has a bandwidth of more than the conventional 10% - 15% (e.g. patch antenna) is broadband. But of course, if you're comparing to UWB antennas, definately it will seem 'narrowband' to you! ;)

So now considering a dipole structure over a ground plane, the usual lambda/4 objective still pertains. BUT, you can reduce that dipole-to-ground spacing with a suitable material. Now when that happens, the usual microstrip patch antenna analysis comes in. Of course, trade-offs also occurs, so you must be careful.

Now, on the other hand without proper design, when you place any scattering/radiating structure too close to the ground plane (e.g. in this case, maybe a commercially-off-the-shelf FR4 PCB thickness depth), you'll run the risk of 'shorting' it out. This could explain your "problem that the impedance, both real and imaginary, are almost zero". Your design probably shorted out certain modes of operation.

And for "about the space between two triangular patches", as long as it is no wider than lambda/4 to your designed half-wavelength bow-tie's fundamental operating frequency will do. Even having said that, I don't think there really is a 'specific' formula. And yes, I would recommend a parametric study on the spacing to see which suit you better. Would any readers care to comment?

I hope these helps,
Dave[/QUOTE]