[ask] determine bandwidth in IE3D

Hi, I'm using IE3D to simulate patch antenna...
I have get the S11 return loss simulation result, but I don't know how to determine the bandwidth of this antenna from it resonant freq.
can anyone give me a clue how to figure it out this bandwidth...
thanx...

Hi,

The bandwidth of an antenna refers to the range of frequencies over which
the antenna can operate correctly. The antenna's bandwidth is the number
of Hz for which the antenna will exhibit an SWR less than 2:1.
The bandwidth can also be described in terms of percentage of the
center frequency of the band.
BW = 100 ×(FH − FL)/FC
where FH is the highest frequency in the band, FL is the lowest
frequency in the band, and FC is the center frequency in the band.

Added after 56 minutes:

In Ie3d U can add flag or Marker & find the range of -10dB Returnloss.

with above said formula u can find out the percentage bandwidth.

Yes. Users can add flags and markers using mouse on the curves for s-parameter display. Then, on the marker list on left hand side, you can fine tune the exact location (x or y) of each marker and find the difference from any 2 markers. The dx of 2 markers is the absolute bandwidth. Using the formula in baraguru's posting, you can find the relative one. Regards.

Hi balaguru thavamani,

First thanx for the answer, but actually I know that definition of bandwidth...
I just though that there is somekind of feature in IE3D, that automatically could show the bandwidth value...
because I'd used another simulation software before IE3D that provide this feature, well at least it could give auto mark to fl and fh (lower and higher freq range)...

OK, back to reality, how I can add a mark/marker in the IE3D?
because from Modua I don't find those menu...

Thanx...

Hi,

For adding markers,

Check the Check box of the required parameter in modua say dB[S(1,1)] for
Returnloss & By sliding over the graph and clicking the left mouse button we can add markers.

As Mr.Jian said we can able to fine tune for the required frequency by double clicking the marker values which will be displayed on left hand side of the Modua.

We can able to edit both X and Y values for fine tuning.