How big should the wire radius be in MOM?

Hi

i have been struggling with MOM for some time now. It seems that the S11 parameter is depended on the radius of the wires i use.

I saw that a good value for a coaxial wire is a radius of 0.5mm

I also need to use simple wires connecting the edges of two patches on a substrate(microstrip antenna). Does anyone know how big should be the radius of this wire?

What is the MoM code that you are struggling with?

Concerning the feeding wire radius: if you are using a wire and placing a delta generator (voltage source) on that wire, then it's important to make that wire then S11 depends on the radius of that wire. And dependence is in terms of the electrical size, so 0.5 mm can be good for your frequency range but not good for some other range.

What kind of current approximation for wires your code uses? Is it thin-wire kernel?

Why are you using wires to connect two patches on a substrate?

Can you upload a picture of what you are trying to do?

I am trying to simulate the structure in the picture in order to compare results.

I use the FEKO 5.3 software but it doesnt specify anywere if it is a thin wire approximation. I know that certain constraints must be implemented, such as the ratio of the segment radius to the length should not be too large etc.. Ideally segment = 4*radius.

I first put a wire of radius appr. 0.65mm from the ground to my feed location and then apply an impressed electric field strength along this segment. A voltage gap on a segment.


I think i made mistake by creating wires between the patches. I will try with surface polygons.

My frequency is 2.14ghz. How can i calculate the radius that the feeding wire should have?

I wouldn't put wires on surface of the substrate. Put narrow metallic plate strips instead.

If you put a wire, only the two ends of the wire are electrically connected to the surrounding, which is not adequate for this case. Also, I am not sure if FEKO considers a wire laid on the substrate to be a legal situation.

Wires are good to model one line of current, and that's it.

I hope I helped.