Antenna Types – CompTIA Security+ SY0-401: 1.5

| August 3, 2014


The type of antenna can make or break a wireless network installation. In this video, you’ll learn about various antenna types and when they might best be used in a wireless network.

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If you’re implementing a wireless network, you may need to use different kinds of antennas to accomplish this. In this video, we’ll look at a number of different antenna technologies and see which one might work best for you.

A very common antenna type we see when we purchase some of our wireless access points is an omnidirectional antenna. This is the antenna that simply points into the air. And you get exactly the same type of coverage wherever you happen to be anywhere around that particular access point. The signal is evenly distributed on all sides. That’s why we call it an omnidirectional antenna.

Because no matter where you happen to be, you receive the same signal strength from that antenna. In many environments, this is a pretty good choice because you can put the antenna in a central area. And no matter where you happen to be, you’re getting the same signal strength from anywhere around that access point.

The problem occurs when you want to have a little more signal in a particular area. An omnidirectional antenna is very good at evenly distributing that particular signal throughout. If you want a little more signal in a particular area, however, you’ll need to use a different kind of antenna.

In those cases, you’ll want to use a directional antenna. And as the name implies, this allows you to focus the signal into a very particular area. This also allows you to increase the distance. Because you’re taking all of that signal that normally was set omnidirectionally, and you’re now focusing it all in one particular direction.

This means that we’ll be able to have a very focused signal in one particular direction for both sending and receiving. This means if there are other signals that are off to the side that are not in that direction, we’re not able to send or receive to them very well. This directional antenna is really focusing all of that signal to one particular place.

The performance of an antenna is measured in decibels. This relative measurement means that if we’re able to use an antenna to effectively double the gain out of a particular antenna, that means it increases by three decibels. And you can compare the decibel ratings of different antennas to get a feel for how that antenna might work for you.

One type of directional antenna is the Yagi antenna. This provides us with a way to really focus our signal in one particular direction. And because of that we get a very high gain from a Yagi antenna.

Another type of antenna is the parabolic antenna, where it can receive a lot of signals down a very wide area on this curved back of the antenna. This curved back means that as the signals hit, they’re going to reflect off of that into a single point that is reflected right into the point of that antenna. So as we’re receiving from many different areas, we’re able to instead focus those signals down and receive much better for that antenna.

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Category: CompTIA Security+ SY0-401

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