Hey guys, thanks for coming back to Wi Fi fundamentals, location and analytics. This course will help you to muster the air. We have come to one of the most intimidating stuff in Wi Fi networks and tennis. Why do I need to learn of antennas? It's there and it works. Well no.
Antennas are key to your understanding of the wireless environment. Just think about it. Without antennas, wireless communications could not be born. their wealth work is fascinating and they are everywhere, internal and external. The antenna is where the radio waves hit the air for the very first time setting the stage for RF performance antennas pattern are crucial to your Wi Fi deployment. If you want to cover a hallway, you will probably use a directional antenna.
If you wish to cover your hotel lobby, you will use an omni directional antenna. A few facts that are good to know. antennas don't add power to the RF sing. They focus it in different directions we call it a game. In fact number two if you wish to double the range of your antenna, you have to quadruple it at six DBI What will you learn we will see how antenna works how they are built, we will learn of key terms gain they rection polarization. We will also learn about the ISA tropic antenna which is the theoretical antenna model Every antenna down nowadays relates to it.
We will look at different antenna types the only directional directional and the dipole antenna. And we will also take a look at how antennas are used in penetration tests. Do you remember pendulum work pendulum is a device that when you apply a very small force in a specific frequency, it induces a very large motion that repeats itself. This phenomenon is known as a resonance. That's exactly what antennas are doing. They have a resonant and optimal frequency.
Antennas role is quite simple. They turn electromagnetic wave to electric energy The opposite. You can think of antennas as a metal road that is connected to an electrical source. That source usually uses alternating current AC. As the electrons move in the antenna, an electric current isn't used and the lines of magnetic flux are created and radiated into the air. The frequency at which the current goes in and out goes in and out into the antenna is actually the frequency of the antenna.
And remember, frequency and wavelength are related. antennas length has a direct linkage to its ability to tune, receive and transmit data frequency, a bigger antenna will tune lower frequency make it small, it will have a higher resonant frequency. The size of the antenna has to be proportional to its wavelength. If the WAV produced by the transmitter is at the right frequency, it will resonate. And the signal received will add to that of the antenna and you will get a stronger signal. If I want you to remember one thing is that wavelength equals antenna size.
Antennas by design are created to support different frequencies. This is why they're usually a quarter or a half wavelength of the frequency for which they are designed. The signal will have a large pick The Chosen frequency, it will resonate better. antennas are built to support certain frequencies. their physical length is built upon the proportions of the frequencies wave length. One example that is very common is the dipole antenna.
It is also called a half wave dipole, as its length is the half the frequencies wavelength. Coming up part two of antennas