hfss matching component

Hi folks,

This is my first post, so please be gentle :)


I am having trouble setting up a model with HFSS 9.

How do I successfully set up a Lumped RLC port with a square loop antenna (copper tubing). I have to have a capacitor and a resistor connected in parallel to both ends of the copper tubing.

Is it even possible?


Any help is much appreciated.

Cheers

Hi,

When you are using HFSS, you should bear in mind a theory
"Simple is the best"
It is wise not to draw your simulation structure so complicated, since it must spend you so much time on simulation, by the way, it is not easy to draw wrong structure or do a wrong simulation.
I would suggest you to separate its as in two parts:

1. Antenna design
2. Passive Component matching ( your resistor or capacitor etc and etc)

Regaring to Antenna design, I assume that you are mounted on PCB instead of 50ohm coaxial cable, if this assumption is hold, then you could use lumped port for simulation, but you should define the size of lumped first. If it is connected to 50ohm coaxial cable, then you had better to draw coaxial cable in HFSS.
Just make those port in touch with your structure is okay.

Furthermore, as you mentioned that your antenna is loop antenna, and it is conencted in parallel with passive component, then it probably balance mode, then you should define two ports, if not, unbalance mode, then one port is okay.

Finally, after antenna design, you could go on your passive component matching, I would humbly suggest you using microwave office or any simpler software to import solution file from HFSS to that software to do matching.

Anyway, I hope that I could really help you. Good Luck!

Best Regards,
Le

Hi Le,

Thanks for that information, it is a big help.

The problem I have is that I only have HFSS software to work with so I cannot use Microwave office. Is there anyway I could include the parallel resistor and capacitor connections using only HFSS?

I have tried creating a parallel object in my model that connects to both ends of the copper tubing. I have assigned a single Lumped RLC port to this object. Is this incorrect?

Whenever I try to run a simulation I get an error message stating that HFSS is "unable to recover all surface triangles"

When I remove this object the simulation runs fine.


I am bit puzzled with this :(


Can anyone shed any light on this error?

Regards

i think it has something to do with boundary definitions or your mesh refinement. try chaning the lambda refinement value

"unable to recover all surface triangles" most probably means two of the points specifying a triangle are too close to each other thus the triangle becomes a line under the "resolution" of HFSS. the reason might be:
1. the object (you removed) is too small
2. the object (you removed) is specified with an edge/point that is too close to edge/point of another object.

Try different way of building the model (pay attention to the snap feature), and zoom zoom zoom .... to verify.