A WiFi® amplifier is a device that can improve the strength of a wireless networking signal. The term WiFi® amplifier can refer to a replacement antenna that produces a significant signal gain, though repeaters, and even passive antenna augmentations, are sometimes referred to as amplifiers. Antenna based amplifiers are typically designed to replace stock antennas on wireless routers. These amplifiers typically require an external power source to boost the signal. Repeaters are separate devices that can be placed at the edge of a wireless signal to rebroadcast it into a dead zone, while passive antenna modifications often take the form of parabolic dishes.
WiFi® is a technology that is used in computer networking to wirelessly expand the network over radio frequencies. These networks can provide fast, reliable transfer speeds if a direct line of sight exists between a wireless router and a WiFi® card in a computer. Connection speeds and reliability can both suffer as the distance between these components is increased, and can fall off sharply when walls, ceilings, or floors are in the way. In order to provide the signal enough power to cover greater distances, or pass through obstructions, a WiFi® amplifier can sometimes be used.
There are a number of different devices that are commonly referred to as WiFi® amplifiers, though most of them do not actually amplify anything. One type of WiFi® amplifier is typically used in conjunction with a wireless router. These devices are often installed in place of the factory antenna, and contain circuitry that is capable of boosting the transmission signal. Some of these amplifiers can also be installed in-line with a high gain antenna, which can improve both transmission power and the ability to receive weaker signals.
Another type of component that is sometimes referred to as a WiFi® amplifier is technically a repeater device. WiFi® repeaters do not typically amplify signals, but they can have a similar effect. These devices receive a wireless signal and then rebroadcast it. This can have the effect of expanding the range of a WiFi® network, or broadcasting it into a dead space caused by walls, floors and other large obstructions.
Some passive antenna modifications are sometimes referred to as amplifiers as well, even though no actual signal amplification takes place. One device that fits into this category is the parabolic antenna, which can allow the WiFi® card in a computer to receive weaker signals than a traditional antenna would be able to. These antennas can be purchased commercially, though it is also possible to construct a parabolic modification for an existing antenna by using simple, inexpensive components.