Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: How long is the signal range? I'm about 30 feet from my Belkin N900DB router
Document: Mine is about thirty feet away- other side of the house- and after moving the router about a foot forward on its table so it wasn't fighting at an angle to get through a hallway wall, the signal was perfect.
Works very well, considering that my router is less than 10 feet away in a closet. Never has dropped a signal since I purchased the unit. Easy and quick installation in the smaller PCI Express slot. Extremely good value for money!
Using it in office ( router is 20 feet away in different room ) for about two months now, and am getting excellent signal strength as you should expect. Super easy install. Used Windows drivers. This is my second Rosewill wifi card, and have had a good experience.
I bought this as a replacement for an older D-Link PCI adapter that was having a hard time hold more then a bar of signal, 25 feet from the router. This Rosewill card installed and worked flawlessly, went from 1-2 bars of signal to 5.
Shipping was fast and the product is a good buy. I have a wireless router on the second floor and my computer, which i hocked up the wireless adapter to, has no issues. Full range of bars on the signal indicator. Great product.
This wireless adapter wont get signal and when it get it lost  after 2 minutes, if you are a new builder like me DO NOT BUY IT!! spend a few buck more and get QUALITY! my router is 12 feet from my computer and this junk dont get any signal, even my daughter nintendo dsi get more signal that this junk.
Getting 144mps  right outta the box. very pleased. and i am outside in my man cave about 60 feet from the house. great range!!! and it works in ubuntu!! i expect greater speed in windows.
This would be random every few days. I know it wasn't an issue with my modem because my other devices had internet access just fine with it. So it became an annoyance then finally after of couple of more weeks of that it just went kaput would not access the modem at all; I gave up and removed it. Seems that this device is from China and has no meaningful technical support. I will admit the antennae's in the back of the adapter are nice and long; have a nice range.
I've never had this adapter (and i'm running 3 of them in different machines) drop a connection once. It's got great range and speed, and doesn't take up much space in the PC. Great product all around at a very reasonable price.
I bought this for a client of mine who could not get wireless to his upstairs with various products he would either get 1-2 bars or not connected at all. It baffled me since his desktop is literally 15 feet above his router but his house is over 100 years old so I guess the materials don't play nice with WiFi. This is what I did.
Answer: The signal range is way over 30 feet. Mine is about 20 feet away and through two walls and my signal is fine. The only trouble is that, after two months, the adapter was suddenly unable to connect to my wireless network. This could very well be a user issue but, anyway, back to your question: Yes, it works awesome within 30 feet.