Two same separate antennas in HFSS

Hello,

I have a question for which I can't find the answer nowhere. The thing is that I am trying to simulate two same separate antennas in HFSS together to see the effect on radiation pattern. The problem is if I make two separate ports (one for each antenna) only one antenna is active and the other just don't want to radiate.. If I make a rectangle below both antennas and assign a port it is the same... again only one is working.. is there a way to make both antennas radiate at the same time?

Thanks in advance.



PS:

I couldn't find the answer on forum. Also I saw the post "HFSS - multiple ports", but it doesn't solve my problem.

Could you make a one-port feeding structure for both antennas? For example, if you have two dipoles, you make a symetrical feeding structure (transmission lines) to both dipoles, but excited by only one port.

rfmw, thank you for your answer.
I was trying to learn something about transmission lines, and do as you suggested, but I found out that this subject is quite complex, and it would take me at least one or two weeks to learn enough to make this work that way. It is a lot of time for just one little think. I also found one way to do this (attachment), but I don't know, if it works as it should. I basically made a rectangle under both antennas, and used Driven Terminal mode. Than I assigned wave port, and chose one antenna as conducting object, and one as reference conductor. In this way both antennas radiate, but I don't know if this is right... also the radiation patten changes drastically when changing the size of the wave port.... is this a solution?

I had a look at your structure. You would like to see the radiation pattern of a group of two dipoles, right? I don't think your waveport solution is going to work. It's bigger than both dipoles (monopoles), therefore it affects a lot the antennas.

I think you should first define what you want to do, since this is not clear from your structure. Making the antenna as a standalone rod or one cylinder is not the right way to go, sorry.

I knew it is a bad solution... anyway... I found a new one, and now I think that it should work properly. The radiation pattern is still not perfect, but I will improve it. I attached my idea below, if anyone is interested. One with two lump ports and one with two wave ports simultaneously.

The problem was, because the second port was inactive by default. To activate the port you should go to HFSS->Fields->Edit Sources, and set the Scaling Factor of the second port from 0 to 1. This activates the second port.

I think that this is it..

Here is also the improved version. In previous version the monopoles were too thick, and one port should be set to phase offset 180 degrees. Now the radiation pattern looks much better.