An antenna or aerial is used to send and receive radio frequency signals. It is usually divided into two categories. The first category consists of the directional antenna. Also called bidirectional or quad directional, a directional antenna gets signal response from a single source only. Surprisingly, it offers better reception from a weak signal source. This source can be a TV broadcast station. The second category consists of the omnidirectional antennas. These do not have to be pointed at a given direction in order to work. Unfortunately, they demand a stronger signal from a broadcasting station. The omnidirectional has indoor and outdoor applications.
For instance, it can be used to boost internet signals for Wi-Fi devices. Because of having poor signal responses, omnidirectional aerials should be boosted with an amplifier. The amplifier is a recent invention that has made the omnidirectional aerial so popular. You can think of an amplifier as a directional antenna that uses a technologically advanced processor to filter the sound on a signal of an existing omnidirectional antenna. Prior to buying an aerial, you should know the purpose you want it to fulfill. Perhaps you want it to boost the performance of your TV or mobile devices.
Outdoor antennas will obviously offer you the best performance than indoor types. The latter are usually tiny and made to be put on top of a TV set or next to it. The former are big and are designed for the roof or attic regions. Because of their bigger surface area, they are able to receive stronger waves than the tiny indoor equipment. So they offer a higher gain (a measure of signal strength an antenna can deliver to a tuner). Indoor equipment performs poorly not only because it is small but also because of the interference it receives from walls and movement of humans in the house.
The best types of outdoor antennas are HDTV (high definition TV). To receive a clear digital TV signal, you should get yourself a HDTV aerial. This one will receive all HD channels you would love to watch. Note that HD signals are conveyed along the UHF (Ultra High Frequency) band. With both regular and HDTV aerials, you will get signal bounce or multipath because of tall buildings, trees and other objects. Multipath causes the wave to reach your HD antenna many times and at different intervals. To reduce this problem you should have your equipment fixed as high as a position can allow. Note that your HDTV will receive both analog and digital signals.
There are amplified and non-amplified products too. Which ones do you want? If you are having poor signal reception, you need a product that will overcome height, size and distance challenges. Amplified antenna options are known to boost the gain. Both indoor and outdoor amplifiers exist. They can be bought for existing equipment. If you want to buy a new aerial, many modern types have built-in amplifiers. There is one you should know though, about an amplifier. It will amplify both the noise and the signal. If they are overwhelmed by strong waves, your reception will become worse. Thus you are advised to use these supplemental devices when it is really necessary.