monopole PCB antenna, HELP needed

Hi,

I am trying to design a monopole PCB antenna using HFSS. However, I am not familiar with the software as well as concepts of monopole.
1. regarding the HFSS, any friends knows how to create a right structure? I use a thinkless rectangle to simulate the monopole, a box to simulate FR4 PCB, and another sheet to simulate the ground. Both ground and monopole i set to perfect conductor. Then I put a large sphere outside and set to radiation boundary. After that i set a lumped port btn the monopole and ground. However, I was only able to see the S11, but don't know how to view the radiation pattern.
2. in my understanding, monopole is 1/4λ, the frequency is 900M, so λ=33cm, 1/4λ=8.25cm, with ξ=4.4, i use the ADS LineCalc to calculate the length and width of the monopole. However, the results deviated a lot and reach 1.4GHz. Anyone knows how to calculate monopole dimension with PCB substrate?

Help needee! Thanx with regards

JY

monopole lenght is nearly independent with PCB thickness, because the printed monopole should not be put above the ground plane.


Just a question to ask, is your antenna above ground plate?

Hi, geppei,

The monopole which i'm intending to design is not above ground plane. For I suppose this will generate a field pattern both on top and below the substrate.

Regards

A similar kinda planar monopole antenna has been designed & tested in IEEE microwave & RF journal. check previous 2 issues. for various ground plane dimensions the change in characteristics is also discussed in the article.