What is Antenna Theory?

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In today’s digital world, we are completely surrounded by amazing technologies that help to make our lives easier. The strange thing is that many of us have very little idea of how a lot of this technology works – we just kind of accept it!

For instance: do you really know how a CD Rom stores data? Do you understand how a computer works?

How about WiFi?

Often when we delve into this stuff, we discover that it is not only extremely interesting, but also rather useful to know. This is certainly the case with antenna theory, which tells us how antennas work and therefore how things like satellite phones and digital police scanners work. Even Bluetooth!

Read on and prepare to marvel and the incredibly smart technology that all of us rely on every day!

The Basics

To understand the basics, we need to know what a wave is, and how it can be used to carry data.

Essentially, antennas are used to both emit and receive data in the form of waves. These waves work just like ripples in water, except they don’t need any water in order to travel. Instead, they work by affecting the invisible ionosphere all around us – the electromagnetic field that allows currents and charge to travel through our atmosphere.

Small pulses of electricity exit antenna and create an antenna radiation pattern – a graphical representation of that wave. This wave then propagates through space until it reaches another antenna. That antenna will then interpret the pattern of that wave, and thereby translate it into the original spoken word, music, image, file, or anything else.

This conversion is made possible because the antenna itself will also contain a certain amount of electrons. These electrons are then excited by the environmental radiation and encouraged to move. As they do, the movement eventually creates an alternating current, which is able to light up pixels on a display, or cause a speaker to vibrate in order to convert the energy to soundwaves.

This basic technology explains how everything from walkie talkie technology, to phone masts work!


Still with us?

While this might seem (hopefully) simple, there are actually a number of technical terms used to describe everything that is going on here. Here are some of them:

Wave: The wave is the pattern that travels through the electromagnetic field.

Frequency: This is the number of waves that occur in a set period of time. Are they long, slow waves? Or are they short, fast ripples? In other words: is there a low or high frequency?

Wavelength: This is the length of the wave specifically. You might describe something as being longwave or shortwave. A shortwave radio therefore, is a radio that listens out specifically for these shorter waves.

Amplitude: While the wavelength describes the number of waves, the amplitude describes how ‘loud’ those wavelengths are. Do they have high peaks and deep troughs? Or is there very little movement?

There are many more terms that can be useful to understand here from directional to omni directional (does the message spread out or travel in a straight line), to phases (a point in time on a certain wave).

If you found this interesting, then we recommend that you continue your research and perhaps invest in a police scanner. We’ve only just scratched the surface of this fascinating technology!

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