cst helix antenna

Hi All,

Someone has told me that it is impossible to place the Helical Antenna for EM simulation because it is hard to model the helical structure. Is the statement true or not ?
Best Rgs

You can simulate the helical antenna by the NEC or SuperNEC software (anyway I have seen the corresponding SuperNEC example), but I don't know how it will be accurate.
With responce,
Kit-the-great

But, how can we start if we have choosen some common ISM band frequency in US (900MHz, 1900MHz, 2.4GHz and 5.8GHz) ? Are there limitation on the spacing between each turns? Any valuable advise!

Hi Rayengine,
I know that helical antenna was simulated by CST MWS. In fact there is an example about that antenna in the installation CD. The conformal FDTD or FIT allows to simulate this kind of model.
Regards.

Hi Rayengine,
I\E3\D also has a helical antenna as an example.
The difficulty with many simulators is that they cannot manage curved structures. But curves and curved surfaces can be approximated with staight segments and pieces of planes. In the case of that example, the approximation is constructed with 12 segments per turn.
C\S\T claims to simulate very accurately curved structures without those approximations, but I have not experience with it.
Regards
Z

I have simulated 2.4 GHz Helix antennas using CST MWS. The correlation with measurements was surprisingly good.

Hi GaAs FET,
Can you share with the forum with the design file on how it construct?

Reyengine, here you simple helix antenna calculator on:
http://www.csgnetwork.com/antennahtcalc.html

XFDTD also has an example project for helix antenna.

you may like to use empire from umist.

hfss can solve it.

I agree, I use H/F/S/S for this problem. However, drawing the geometry is pretty difficult but the results are good.

Is there a command for drawing Helix in Ansoft HFSS?
I remember Agilent HFSS has one.

In 4NEC2 you can find Helix antenna example.

i think you can use 3d tool, such hf55

You can if you are designing conformal 3d helical antenna...

You can also solve with winnec...

easy with CST - geometry takes only a few minutes...

I atended a seminar organized by CST, where they presented their softwares, now I have collegues that use CST and have good results, but I know other engineers that use IMST,QWED or Fidelity and they also get excellent results.
Now I listened quite carefully to CST presentation and they convinced me that they use precise geometrys like the real model they try to simulate(compared to stairbox case), but what they did is render a perfect geometry and move the aproximation to the electromagnetic simulator calculation.
So when using a staircase simulator the simulation is precise, but the geometry tries to aproximate the reality-so results are a aproximation,
CST removed the aproximation from the geometry and transfered it to the simulation itself.
The results are pretty good for a good operator, but other simulators will get you similar results, some maybe more precise. But we are engineers so we need enough precision to do our design and can leave absolute precision to pure academics.
CST for sure have for the time being the best modeller, but this is changing fast in this competitive market.

Rendering a perfect geometry makes the user feel better, but the result is by no means better.
If staircasing is used, much resource is needed for simulating curved objects. The internal of MWStudio is certainly more complicated.
I read from this forum that CST is keeping its PBA "perfect boundary approximation" algorithm secret. The user would have no way to finding out the disadvantages. This would eventually hurt the product.
The meaning of "enough precision" is never precise. Years ago a pocket calculator was good enough.