helf for printed monopole antenne

hi,

i designed a printed monopole antenne for mulitband application. i used the microstrip fed. actually i found that the dimension of the ground plane has great effect on the matching, how can i slove this problem. and i also found that the length of the ground plane and microstrip fed line can effect the resonance frequency and match,too.

Added after 1 minutes:

sorry again, my e-mail is briannama@gmail.com, if you have any good suggestions, pls tell me, thanks a lot

Added after 27 seconds:

briannama@gmail.com

Hi Briannama,

I hope the attached paper can help you in this case.
plz refer to the link:
https://www.edaboard.com/viewtopic.php?p=799762#799762

Additional discussion, from my opinion, the length of truncated ground plane is the same meaning to the length of microstrip line. As you know, antenna can be assumed as a opened circuit, so the length of microstrip line will determine antenna input impedance and it also can affect strongly to antenna characteristics.

Do you agree?