Sector Antennas

In geometry, a "sector" is a "slice" or "wedge" of a circle. Picture a slice of a pie being lifted from the pie, and you get a visual image of a sector. A sector antenna is a directional antenna designed to cover this kind of geometric shape.

A 60 degree sector antenna covers 60 degrees (1/6) of a 360 degree circle, while a 90 degree sector antenna covers a fourth of that same circle. The radiation areas don't end abruptly at 60, 90, or 120 degrees; these have a few degrees of overlap so you could, for example, use three 120 degree sector antennas for full coverage of a circle.

For 802.11 (Wi-Fi) applications, sector antennas have a range of about 4 to 5 km. We offer sector antennas in 60, 90, and 120 degree configurations and have them in stock for immediate shipment.

You can easily reduce the coverage of the device by making any of a few simple errors. So that you don't make those errors, follow these tips.

1. Try to be central. A common mistake is sticking the device in a corner, typically where the facility's broadband service enters the building. This can put most of the coverage outside of your office, leaving weak signals in some areas.
2. Install a shelf for it. That's right. Buy a small wall shelf kit and put the device up high.
3. Avoid noise sources. Don't put it next to another source of RF.
4. Avoid RF absorbers and blockers. Steel columns and other obstacles can greatly diminish signal strength.
5. Be sure you properly route and support the Ethernet cable to this device.
6. Route and support the power cable. One reason people stick these things in the corner is that's where the AC outlet is. Provide a new outlet just for this, so you can put it where you want it. You can buy easy to install surface mount raceway for this purpose.

Some system administrators use a combination of long SSID and complex password when setting up a wireless system. This is a mistake, because a long SSID makes it difficult to add some devices (such as mobile devices with virtual keyboards). Use a short SSID, and let the system manage the password for you.

This brings up another question. Do you need a secure network at all? The answer depends on what your network is used for. If you have clients or customers visiting your premises and you provide broadband access for them, then make it a public network. But for your own internal usage, go with a secure network. Many automotive dealers and repair shops, for example, now have exactly this kind of arrangement.

When network devices fail, many people think it's because of "dirty power" from the utility. While a power spike can certainly knock out network equipment, in small offices the main cause of failure is heat. People stack the router on top of the modem on top of the VOIP switch, all of which are housed in a little cabinet and buried under paper. Don't stack devices, and don't stick them in a cabinet.

Allow for airflow around your network devices (and around your workstations, too). Workstations are often placed on the floor, under a desk. This means their fans suck in dust and you end up replacing a computer at the worst possible time (typically, just as a deadline is looming). While network devices almost never have fans, they also need to be kept up off the floor.

But if heat rises, won't the floor be the coolest place? Yes, heat rises. But dust settles. And an insulating layer of dust on your electronics does not help them stay cool. Mount network devices where they can be seen and are likely to be kept clean.