Empty results in HFSS.

Hi,

I have followed steps given in the below link to get hands-on exp in HFSS.
Hfss Tutorial Dipole Antenna

I didn't get any errors but got 2 warnings which can be neglected.
But I don't see any results when I simulate them in accordance to given tutorial.
All the graphs are empty.

Can you please let me know how to proceed further?
I am stuck and unable to move forward.

Thanks!

If you Dont see any results,then most likely your simulation never finished.

post your files here.i will be able to help you out.

Regards.

Hi,

What files do I need to upload?
Above all, When I designed a new project, when I applied wave port excitation, I don't see any General Tab, Integration Line at all.
I got a pop up window "Reference Conductors for Terminals", asking for Port name and Terminal Naming.
Why is it so? How should I solve this?

Thanks!

Upload your HFSS file shaik

it asks you that question because your solution type is driven terminal and it requires two conductors to set up your port.upload your hfss file i will give you a feedback

Regards

I have attached the .hfss file. I have followed the steps as mentioned in the link.
I faced problem during Excitation ->Wave port.
Finally, I have chosen Quick Report from Results.

Last but not the least, what are the steps to be taken care while creating cylinder/box/spehere/rectangle for radiating structure and feed structure.
How should I select the values of radius, height of cylinder, dimensions of box, sphere, rectangle?

For example, if I want to create a dipole antenna resonating at frequency of 865MHz. I have the only input that is resonating length i.e lambda/2.
Depending on this input, how should I select the cylinder, box, rectangle dimensions?
Is there any Rule of Thumb?
How should I select the radius, gap between the feed structure?
Please clarify my doubts.

While I try to upload the .hfss, it's showing it as invalid file.
Can you please give me ur email id? I will mail u the things.
Thanks in advance.

PS: I have zipped it and uploaded.

Can anyone please respond?

So Shaik

The problem with your design,i can't tell what you were doing honestly,i see there are a number of cyliunders along y and a cylinder along X and sphere's connecting the cylinders along Y direction.if you are drawing a simple dipole.there are two cylinders separated with a distance of feedgap. i have no idea whatsoever what you are doing.

Regards

Hi Chachito,

Since I am new to HFSS, I want to simulate a known and fully described example. So, I have followed the steps as they are mentioned in the link, posted in my first post. That link explained to create 4 cyliders, 2 spheres, a rectangle and a box.

I have come across another link
HFSS Tutorial

When I tried to simulate the same, the validation gets failed as the two cylinders get overlap.

Can you please explain me step-by-step procedure to simulate dipole antenna? I am really stuck and unable to proceed further.
Even I am not getting how to select radius, gap, height etc parameters. On what factors does these values depend?

Request you to help me at the earliest.

Thanks

---------- Post added at 03:19 ---------- Previous post was at 02:59 ----------

Hi Chachito,

Since I am new to HFSS, I want to simulate a known and fully described example. So, I have followed the steps as they are mentioned in the link, posted in my first post. That link explained to create 4 cyliders, 2 spheres, a rectangle and a box.

I have come across another link
HFSS Tutorial

When I tried to simulate the same, the validation gets failed as the two cylinders get overlap.

Can you please explain me step-by-step procedure to simulate dipole antenna? I am really stuck and unable to proceed further.
Even I am not getting how to select radius, gap, height etc parameters. On what factors does these values depend?

Request you to help me at the earliest.

Thanks

Its fairly simple. Dipole is one of the easiest forms of antenna design. follow these steps
Define variables in the project 1.radius of the dipole, lambda,length of the dipole, feed gap,
step2-- draw a cylinder with its coordinates(0,0,gap/2)
step3--draw another cylinder or duplicate the cylinder along the line from above( where the duplicating distance is in the z-direction of a value 'gap')
step 4--draw a rectangle dimensions(-rad/2,0,-gap/2) to (rad/2,0,gap/2)
step5--assign materials--- cylinders assigned pec.
step6--assign lumped port to the rectnagle drawn
step7-- solution frequency and then sweep
step8--sweep your frequencies
step9-- check for your results

the values of the radius is lambda/50, gap=lambda/100, height of the dipole is close to half a lambda

hope that helps.its a most basic form and should be doable.

Regards

I have a Q here.
How did you chose the radius as lambda/50 and gap as lambda/100? Actually, I am confused about the selection of radius and gap.
Finally, what are the results to be captured?

i am sorry to say,but for a thin dipole radius of less than lambda/50 is considered appropriate, gap is chosen very small inorder that it doesnt affect the actual height of the dipole so as small as possible. these were just numbers you could do a little higher or lower around these values.what are the results to be captured? where do you want your antenna to be resonate.you should be able to see resonance around those values.

are you into Electromagnetics/antennas/microwave or is this field completely new to you?

Regards

I am new to Antennas. I had moved to antenna design recently.
I have checked the results but couldn't infer by seeing the radiation pattern when plotted as freq as the primary sweep. When I plotted radiation pattern with phi as primary sweep, I could see the radiation pattern as circle which means radiation is in all directions. But I couldn't infer similar meaning when plotted theta/freq as primary sweep. Can you help me here in this aspect?

Thanks!

post your file's here i will run a simulation and let you know.

Regards

I have attached the file. My resonant frequency is 865~867MHz.
Please let me know what all parameters needs to be checked.

Unfortunately there are so many things to be pointed out,
1.when you define variable they have to be defined globally not locally. define your variable in project---project variables(each variable is defined with a dollar sign prefixed)
2.Yourr frequency sweep is so small and you know how you have started off at 850 and ended at 870 with a step of 10mhz how many points are those 5. what will you see from these points be more wide with the frequency sweep so you get a better picture of the s-parameters.
3.integration line of the source was not properly defined.don/t change any values of the lumped port let it be.
and more over instead of PEC you can also try PerfE boundaries on your cylinders.

Hope i am helpful

Regards

I tried to include S sign as prefix to variable. But its not allowing me to do so.
I have increased the sweep range from 100M to 1200MHz. I changed PEC to perfect conductors.

One more Q, what should one do to decrease the VSWR in their design? Usually it should be less than 2.
If it is more than 2, what changes can we do for best results?

Thanks!

Well for any antenna vswr characteristics depend on the characertistic impednace and the impedance load impedance. only way you can get resonance is to change the characteristic impedance,which here in this case is based on the length of the antenna.

well about the prefix,i am quite confident that you are not doing it right,from what i have seen.you have to first add the variables in the project variables. how do you do it? Project---Project variable and then add variables.

Regards

I tried to make all variables as global by adding prefix S. But I was unable to change existing local to global.
I will change the length and simulate the results and check the same.

Well i would say ,start from scratch again and put down the mistakes and errors that were from the first one and make sure you dont repeat them again

Regards

Yep, I am doing from scratch again. will post again if I get some queries.