how to set the port about 6 order fractal antenna in CST MWS

[no4baseman]

First, i design a 6 order fractal antenna, 100mm*100mm about the size, by using CST MWS, and i wanna know how to set the waveguide port of the antenna.

secondly, according to some papers, the resonant frequency of 6 order fractal antenna should be 100MHz, but it need a lot of time to simulate, so i wanna see the result and at the same time try my best to save the time, so i hope to know whether using CST MWS to simulate is a sound method. If not, Would you like to tell me which software is better for simulating 6 order fractal antenna?

I would appreciate your help. Thank you!

the picture of the antenna:https://obrazki.elektroda.pl/45_1164978942.JPG

 

[RFSimulator]

Re: how to set the port about 6 order fractal antenna in CST

Hi,

MWS should be O.K. for this kind of stuff... The question is only if the TD Solver is the best choice. The model is geoemetrical complex. This is certainly a "pro" for the TD Solver. On the other side, the signal line (the fractal antenna) is rather long and the signal run time + the resonante behaivior might result in a long time signal. This might be a "pro" for the FD Solver.

Did you try to use the FD TET solver on this? How many TETs does this example have in this case? maybe you can post your desing here (Mod File or SaT geoemetry) and we have a try with different solvers?

F.

 

[adel_48]

Hi no4baseman,

I think for such fractals (this is a hilbert fractal as I recall), there is a strong coupling between neighboring slots. This will probably lead to very long simulation time if a time domain solver was used. I agree with RFSimulator that the frequency domain solver will be the most suitable solution.

Also, since this is a planar structure, perhaps you would like to consider using Zeland IE3D. It might be very useful for such structures if your feeding can be modelled in it. (you did not clarify the feed in the drawing)

regards,
Adel

 

[no4baseman]

Re: how to set the port about 6 order fractal antenna in CST

Hi, first, thank you for your advice.

In fact, I only use TD solver to simulate the antenna, and as a result, to save the time and decrease the complecation, some warnings happen(picture 1). Now, according to your advice, first, i wanna use FD solver in CST MWS(after all, i am familiar to MWS); secondly, today i install Zeland IE3D, and try a new method to simulate.

Thank you for your help again!
regards
no4baseman

picture 1:https://obrazki.elektroda.pl/35_1165034853.JPG

 

[itzikhaim]

Re: how to set the port about 6 order fractal antenna in CST

Hi no4baseman !

If you want to simulate a monopole fractal antenna u can save, by factor of half,
the time consuming of the simulation.
In that case you have to bulid a ground and then to run it with a WG port on a coax port (which have E-field boundaries on the outer coductor of the coax which merging with the GND plane).

Secondly, you will get only the half plane result (the half bellow the GND makes the E-field and H-field to be zero) of the far filed pattern.

Good luck !