Lump port excitation in CPW fed Patch antenna

Hi,

I am simulating a CPW fed Patch antenna in HFSS at 60 Ghz. At first I used wave port for feeding the CPW according to the Port_Tutorial_CPW of ansoft, and got very good results. My antenna resonates almost at 60 Ghz.

But now when I use Lump port in the same design, My result changes drastically. Radiation patterns of the antenna remain the same but the return loss is very unusual. My antenna is still resonating at 60 Ghz meaning the minimum return loss is at around 60 Ghz but the return loss is not smooth and has a lot if dips.

Can anyone explains why this happens because I believe that even with the Lump port excitations the return loss of the antenna should be the same as wave port excitations. Please correct me if I am wrong-

Thank you so much in advance.

Waiting for response.

and yes one more thing: with lump port, my design is taking tooo much time to simulate. What is the reason for this? Is there a way I can reduce the time of simulation

Hi rabiazainab,

Have you confirmed that the wave port and lumped port are exciting the same mode?

Hi,

How can I confirm that ? I mean how can I know that the mode eccited by both is same ?

The "Port Field Display" in the left-hand menu will show you the mode that it being excited. You may have to increase the "Scale Factor" in order to view the vectors properly.

thanks i got it...no the modes were not same. thanks for the help