how to down the frequency of a ultrawideband(UWB) antenna to match the index

[Tomsin yin]

hi guys
now am designing a UWB antenna and the work frequcncy is 2~10Ghz,but when i simulate it,i got a good result from 3Ghz to 11Ghz.so can somebody help me to give me some advice about that how to obtain the perfect result in the lower limit frequency,that~2Ghz.my design and simulation is done in CST.**broken link removed**
ty in adcance.

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am sorry for that the uploaded file is not correct,the correct file as follow:

 

[chuckey]

If you just re-scale your aerial from 11 GHZ to 10 GHZ at the top end, you re-scale the bottom end from 3 to about 2.7 GHZ at the bottom. :-(
Frank

 

[Tomsin yin]

hi chuckey
thnx for ur help,so chould u give me some advice about how can i get the good result at the frequency 2Ghz.