Some things to try:
Go to Settings>Wi-Fi and turn Off. Then while at Settings>Wi-Fi, turn back On and chose a Network.
Renew IP Address: (especially if you are drooping internet connection)
• Launch Settings app
• Tap on Wi-Fi
• Tap on the blue arrow of the Wi-Fi network that you connect to from the list
• In the window that opens, tap on the Renew Lease button
Potential Quick Fixes When Your iPad Won’t Connect to Your Wifi Network
http://ipadinsight.com/ipad-tips-tricks/potential-quick-fixes-when-your-ipad-won t-connect-to-your-wifi-network/
Fix WiFi Issue for iOS 7
http://ipadnerds.com/fix-wifi-issue-ios-7/
iPad: Issues connecting to Wi-Fi networks
http://support.apple.com/kb/ts3304
iOS Troubleshooting Wi-Fi networks and connections http://support.apple.com/kb/TS1398
iPad: Issues connecting to Wi-Fi networks http://support.apple.com/kb/ts3304
WiFi Connecting/Troubleshooting http://www.apple.com/support/ipad/wifi/
How to Fix: My iPad Won't Connect to WiFi
http://ipad.about.com/od/iPad_Troubleshooting/ss/How-To-Fix-My-Ipad-Wont-Connect -To-Wi-Fi.htm
iOS: Connecting to the Internet http://support.apple.com/kb/HT1695
iPad Wi-Fi Problems: Comprehensive List of Fixes
http://appletoolbox.com/2010/04/ipad-wi-fi-problems-comprehensive-list-of-fixes/
Connect iPad to Wi-Fi (with troubleshooting info)
http://thehowto.wikidot.com/wifi-connect-ipad
You may have many apps open which can possibly cause the slowdown and possibly the loss of wifi. In iOS 4-6 double tap your Home button & at the bottom of the screen you will see the icons of all open apps. Close those you are not using by pressing on an icon until all icons wiggle - then tap the minus sign. For iOS 7 users, there’s an easy way to see which apps are open in order to close them. By double-tapping the home button on your iPhone or iPad, the new multitasking feature in iOS 7 shows full page previews of all your open apps. Simply scroll horizontally to see all your apps, and close the apps with a simple flick towards the top of the screen.
Cheers, Tom 😉