Hi I am one of the experts here at just answer.com
I have a couple questions
1) Is the Ipad in a dock when this happens?
2) Are you playing any games on it when this happens?
3) Does it happen while you are surfing the internet?
4) Does this seem to happen after the ipad has gone into sleep mode?
One question about your Router is it a dual band in otherwords does it put out two wireless networks?
Now unfortunately there is a known issue with a number of Ipad having this problem of dropping signal. Apple has said they will be issuing a software update that will fix this however they have not supplied a release date for this update yet.
If you recently purchased this Ipad you may want to try swapping it for another one at your local Apple store, or take it to the genius bar in the store where they repair them they maybe able to fix or replace the wireless antenna inside the device.
I wish I had a better answer for you but unfortunately you are not alone with this issue.