no you can't but you can get standalone wifi signal repeaters which recive the wifi signal from your ipad and boost it giving it a wider range
Look at iOS Troubleshooting Wi-Fi networks and connections http://support.apple.com/kb/TS1398
Additional things to try.
Try this first. Turn Off your iPad. Then turn Off (disconnect power cord) the wireless router & then back On. Now boot your iPad. Hopefully it will see the WiFi.
Change the channel on your wireless router. Instructions at http://macintoshhowto.com/advanced/how-to-get-a-good-range-on-your-wireless-netw ork.html
How to Quickly Fix iPad 3 Wi-Fi Reception Problems
If none of the above suggestions work, look at this link.
iPad Wi-Fi Problems: Comprehensive List of Fixes