If I understand correctly, only the iPad is affected so I would recommend this article named iOS: Troubleshooting Wi-Fi networks and connections found here http://support.apple.com/kb/ts1398.
- Be sure that you are in range of your Wi-Fi router (access point).
- Tap Settings > Wi-Fi and turn Wi-Fi off and then on again.
- If unable to do so, see this article.
- Confirm that your Wi-Fi router and Cable or DSL modem are connected to power, turned on, and indicate that they are connected to the Internet.
- If not, refer to your network administrator or ISP for assistance.
- Restart your iOS device.
- Tap Settings > Wi-Fi and locate the Wi-Fi network to which you are connected. Then tap > and Forget this Network. Try to connect to your desired Wi-Fi network again.
- Note: You will need to enter your Wi-Fi password again if your desired network requires one.
- Turn your Wi-Fi router off and then on again2. If your ISP also provides cable or phone service, check with them before attempting this step to avoid interruption of service.
- Update your device to the latest version of software.
- Update your Wi-Fi router to the latest firmware2.
- For AirPort Base Stations, see this article for information about firmware updates.
And this section toward the bottom:
- Move closer to the Wi-Fi router (access point).
- Check for sources of potential interference.
- Remove any case, stand, or other accessories from your iOS device and see if signal strength improves.
- Reset network settings by tapping Settings > General > Reset > Reset Network Settings.
- Note: This will reset all network settings including: previously connected Wi-Fi networks and passwords, recently used Bluetooth accessories, VPN and APN settings.