How do antennas work

Experiments in a reduced-weight environment are a fundamental part of many branches of applied sciences, all requiring to conduct experiments in zero gravity. Could gliders serve as an innovative and low-cost 0-g platform? Jul 28, Blogpost. Immediately after the hacking, ITxx and Engibex Upload your cv Upload your motivation letter How did you find out about us? Antennas for dummies. What is an antenna? How do antennas work?

Oscillation of charges on a dipole wire and generated electric fields. Discover our other thought leadership pieces. Working with Engibex is more like become a part of a growing family. Spontaneous application. Semi-rigid wire dipole antenna. Signals are sent from a transmitter and move along a path toward a receiver, which takes the signal and modulates it to recover the message.

Both of these devices are comprised of different parts, always including an antenna. The antenna you might have to receive satellite television, car radio, or anything else, is a receiver.

The size, shape, and scope of these antennas will depend on the purposes of the sender and the distance that the signal is required to go. In order for a transmitter to send a signal through an antenna, an electrical current must be sent through the antenna and generate a magnetic field.

Instead of simply sending out a signal at a particular frequency , the antenna sends out signals that have either their frequency or amplitude modulated. Frequency modulation FM and amplitude modulation AM are the two most common ways that information is packaged in radio waves. The signal is modulated to contain mono audio information left and right speakers , a pilot tone, AM suppressed carrier information, and text information. The other is an antenna inside the case, usually fixed to the main circuit board, and it picks up AM amplitude modulation signals.

If you're not sure about the difference between FM and AM, refer to our radio article. Why do you need two antennas in a radio? The signals on these different wave bands are carried by radio waves of different frequency and wavelength. Typical AM radio signals have a frequency of kHz kilohertz , while typical FM signals are about MHz megahertz —so they vibrate about a hundred times faster. You need two antennas because a single antenna can't pick up such a hugely different range of wavelengths.

It's the wavelength or frequency, if you prefer of the radio waves you're trying to detect that determines the length of the antenna you need to use. Broadly speaking, the length of the antenna has to be about half the wavelength of the radio waves you're trying to receive it's also possible to make antennas that are a quarter of the wavelength, though we won't go into that here. Blogs Contact. Blogs Need Help?

Search Site. How antennas work Suppose you're the boss of a radio station and you want to transmit your programs to the wider world. Depending on what kinds frequencies of waves we want to send, how far we want to send them, and when we want to do it, there are actually three different ways in which the waves can travel: Artwork: How a wave travels from a transmitter to a receiver: 1 By line of sight; 2 By ground wave; 3 Via the ionosphere.

As we've already seen, they can shoot by what's called "line of sight" , in a straight line—just like a beam of light. It will have the same gain, the same directional pattern, polarisation, the same impedance and other aspects for both transmitting and receiving.

Often it is easier to visualise factors like the gain, and directional pattern using the image of a transmitted signal, but the antenna will have the same gain and directional pattern, etc when receiving as well. There are several basic topics that are common to all radio antenna types and which form part of the basic antenna theory.

Although radio antenna theory may appear to be daunting, a working understanding of how antennas work, and some of the key concepts is very useful. It can be invaluable when setting up a radio communications system or link or even for installing broadcast receiving antennas, or radio antennas for any one of a number of applications. How does an antenna work The purpose of a radio antenna is to convert the power applied to it in the form of a radio frequency alternating current signal into an electromagnetic wave.

In turn, as a result of Ampere's Law, this current will generate a magnetic field. Key antenna theory topics There are several basic topics that are common to all radio antenna types and which form part of the basic antenna theory. Polarisation: Radio antennas are sensitive to polarisation.

In just the same way that electromagnetic waves can be polarised, so too are antennas. It will be seen that some antennas have their elements in a vertical fashion and others are horizontal.