How to measure surface wave

Hi all,

I have a GPS p@tch antenna with a very thick substate. Is there any way of extracting surface wave strength by software simulation or measurement?

Cheers,
Element7k

Hi, buddy

My suggestion is:

- simulation in IE3D with infinite dielectric.
This inf. dielectric layer will guide out the surface waves decreasing radiation efficiency
- making your own code :)
- calculating surface wave f_c and checking if they can be present in your design
- measurement in near field (?)

Just my little suggestions..

eirp

Hi Element7k

use cst add e-field monitor to your simulation
When you display the e-field you will see
The e-field edge effect that make the surface waves
If you succeed to reduce this edge fields you will get
Better gps antenna.

RGZ

PL

For single (or possibly doule) layer microstrip, there some "simplified" formula for the strength of surface wave excited by a printed dipole. I suppose this is helpful. Unfortunately I don't remember the title of the paper. I thought it was written by Pozar and his student.

Hi Eirp,

cheers for the suggestions. I do know the effect can be observed but how do you actually measure the amount of surface waves? Can you provide a starting point for calculation? I've been looking through some of pozar's work as loucy suggested but no luck yet.

Any help will be very much appreciated.

Cheers,
Element7k