Re: HFSS Help (Urgent ).

Take a look at the vivaldi antenna I posted in another thread: [ https://www.edaboard.com/thread283776.html ]

It is a broadband design of a patch antenna, which is aperture fed.

sir,
feeding point is same location in microstrip inset feed, coax feed, aperture feed. Is it right ?

for microstrip inset and coax: yes, the impedance is determined by feed point location

for aperture feed: I do not know

Dear Sir,

what is the affect of gaping between patch and inset microstrip feed and how can we take that value(Wf)?

I do not know the exact relation, but here is a google search on the topic: http://lmgtfy.com/?q=patch+antenna+inset+feed+design

That's It dear / jeeudr

I got warning which is given below.
"Boundary PerfE1 is an infinite ground but does not touch a radiation surface."
please help me to resolve that warning.
thank you.

For which file ? The one I uploaded in post #20 does not have any warnings.

If it is some other file, then, to remove that warning, leave the 'Infinite Ground Plane' option unchecked when you apply the PerfE boundary condition.


It is an interesting design to cover multiple bands. You can simulated the attached file which demonstrates this. I suspect that the radiation pattern / gain is not very uniform though.

Thanks ,..But could u explain plz what have you done

I made the following changes:

1. Added a rectangle between the gap of the ground plane and the antenna feed point and assigned it an excitation (lumped port). This is for the purpose of measuring the power reflections / S11 / VSWR
2. Added an external boundary for entire structure: a box which is atleast 15 cm (i.e. lambda/4 of 0.5 GHz) away from the radiating structure. Applied the radiating boundary condition on the faces of this box. This is for the purpose of measuring radiated fields.
3. Adaptive solution frequency set to 3 GHz and a fast sweep from 0.5 GHz to 3 GHz was also setup. Only fast / discrete can compute the fields in the sweep. Interpolating will not give you the radiated fields at all frequencies.
4. Added an infinite sphere in the radiation setup for calculation of far field. Also, added a field overlay of surface current to reproduce one of the plots from the paper you provided.
5. After this, I just modified your reports files to show the dB(S11) and VSWR correctly.

1 - 3 are essential.
4 - 5 is just something like post-processing to observe more information from the solution.

Try to search for tutorials or workshop lectures on HFSS antenna design. I think that even this forum has many files (buried in different threads) on how to set up simulations in HFSS.