Q:I'm trying to extend Wi-Fi coverage to the corners of my property, but I can only find wireless G range extenders. Is there such a thing as wireless N range extenders?
My wireless router is a Belkin N (MIMO). I would prefer not to have to drop to a G signal if I can avoid it; I'm thinking about budget more than signal strength and speed. Also, do the wireless range extenders need to be tethered to the wireless router by Cat5 or do they pick up the wireless signal and boost it along?
A: It is possible to buy external antennas for draft 802.11n products -- for example, D-Link makes an Xtreme N 2.4GHz Antenna ANT24-0230 to help improve the performance of D-Link's Xtreme N Desktop Adapters (DWA-552 & DWA-556) and Routers (DIR-655 & DIR-660). However, as a rule, today's 802.11n products are equipped with sophisticated, integrated multiple input, multiple output (MIMO) antennas that are not designed for after-market replacement.
This is because 802.11n takes better advantage of multiple antennas -- from 2 to 4 -- to increase throughput, range, and reliability. Range improvements depend on the surrounding environment and how much signal "bounces" off nearby structures, but draft 802.11n products typically deliver twice the distance compared to 802.11g.
You mention wanting to extend coverage to the edges of your property, which suggests that you want to create a larger outdoor coverage area (as opposed to a larger WLAN footprint inside your home or office). Because 802.11n depends on multipath reflections to increase range, it performs better indoors where there are walls, doors and windows to reflect the signal. So it may not provide the extra reach you're looking for when used outdoors.
How could you extend your coverage area outdoors? If it's not feasible to simply install two Wireless N routers (tethered to each other using Ethernet), you could use WDS (wireless distribution system) to connect a downstream wireless N bridge to an upstream wireless N bridge. For example, Netgear's WNR834B and WNDAP300 support WDS point-to-point bridging. You can learn more about WDS in this Wikipedia entry on wireless distribution systems.