2 wire copper conductors

Hi. I'm trying to simulate the real impedance vs. frequency of 2 copper wires spaced 100mils from each other. I attached a photo showing the 2 copper wires near each other and I attached the simulation file.

My problem is the I think the real impedance is too low..it's less than .2 ohms.

I tried different sweeps : fast, discrete, interpolating and various number of steps.

I also tried to change the lumped ports to to renormalize and not renormalize the impedance.

Nothing raised the impedance.

I expect the impedance to be around 200ohms from various online impedance calculators.

Help if you can. Thanks.

What you realy see is the differential input impedance of the 2 wires. these impedance is not the charecteristic impedance of the lines.
In short, you should use waveport and solve for the fields in the port. The solution of the ports give the charecteristic impedance of the lines solved by HFSS.

Hi. I simulated the wavePort with 'Driven Terminal' not 'Driven Modal'.

I looked at the Results-->Create Modal Solution Data-->Rectangular Plot and plotted this attachment. I think this is correct, but I wanted to check. Is this right?

I think the plot looking at Port1 to Port2 is the characteristic impedance. Please let me know.

Also, could you comment on simulating with Driven Terminal or Driven Modal. I've looked this up before, and that's why I chose Driven Terminal for wavePorts.

I also found that the impedance drops if I choose 'Solve Ports Only'

The impedance you see, is the transformed impedance from the end of the two lines to their begining. It is not the charecteristic impedance of the lines. You should use waveports and not lumped ports in your design.

Regards,
Y.A.

I meant to attach this file.

I think a lumped port should still be able to tell me the characteristic impedance. How would you find characteristic impedance if a wavePort can't be used?

Could you please tell me what report result will produce the correct characteristic impedance plot? For example: Modal solution data Report-->Port Zo-->Zo(Port1, Port2) ?

This attachment uses the wavePort.

Yes, lumped port can still tell you the impedance on condition that you put the same impedance as the charecteristic impedance of the lines at the load.
Nevertheless, you should use waveports and let HFSS solve for the port impedance. Try to find some documentation or posts referring to waveports. In general, you should backup the two wires cross section with PEC and draw a integration line between them.