Design a loop antenna

I am trying to model a simple loop antenna in HFSS. (Single loop antenna) I have tried to use the lumped port, but the result is not the same as the theory. why?

Hi;
I think it is better for you to define a current port or voltage drop but could you explain more how did you define lumped port?

Hi,

actually, i am confused about the lumped port, wave port, incident wave source, voltage source and current source. how should i choose to use which excitation is the best and what are their difference ?

Thanks a lot.

hi kevincheng:
choose of excitation depend to your analysing type . if you want analyse your structure on base of scattering matrix parameters and field quantities you should use Ports (wave or lumped) , in this method you should specify the wave entrance location and choose it as port for example space between inner and outer conductive bars of a coaxial cable . but for many lines such as two parallel lines you cannot specify the exact location of wave entrance , so it is better for you to choose your excitation as balun line with current or voltage drop options.
i hope these explanation be clear for you.

Hi aboozar.hamidipoor,

Thanks for your explaination. I think you mean that when we know exactly where the position of the signal to get in, we had better use the wave/lump port, otherwise, we should consider using others.

Then, is there any differences between wave port and lump port?

Dear friends,

how can I define a layer structure with HFSS? Let's say a finite ground 2mm of foam and a rectangular patch....what commands I have to use?

Thanks in advance.

Lupin

Hi Lupin,
The Object in the HFSS should be "real". You can not define a Layer in HFSS but you can build a dielectrical box for it and set its bottom with a E-boundary. If finite ground is concerned, you will have to draw a box with radiation boundary containing all the object.

kayaoo.

dear KevinCheng;
excuse me for delay;
yes wave port and lumped gap port are basicaly different . wave port is defined as the cross section of a wave guide or transmission line , but lumped gap port is such a point source and not the cross section of a wave guide . for example when you are going to feed a horn antenna with a waveguide or coaxial line you should define the cross section of the feed line as a wave port (in fact software suppose the feed line is infinit before wave port) but when you are going to feed a two section antenna such as dipole you shoule define a lumped port between two arms of that antenna by drowing a rectangular cross section between two arms and define an impedance line in arms direction.
i hope this text be helpful for you.
regards.

Hi aboozar.hamidipoor,

Thank you for your suggestion: I used lumped-port for a transmit-dipole.

Now I have another issue:
My receive-loop antenna is supposed to be a magnetic loop.
a) What kind of port should I put on the receive-loop to pick up the Magnetic-field from the dipole.
b) How do I show to others that the receive-loop does pick up Magnetic-field generated by the dipole ?
Hope this helps others too.
Thank you Ab.

Ok,

I've managed to make my transmit-dipole and my receive-loop working together with HFSS.

I used lumped-port for both of them.

To answer my question, the loop picks up both the e-field and the h-field from the transmit-dipole.

My newest question is: how to find the voltage across the gap. I've changed the lumped-port to Voltage-port but after simulation done, I seem cannot find voltage anywhere.