What Is a Wi-Fi Antenna?
A Wi-Fi antenna is a device that transmits and receives radio waves for wireless communications. Antennas, also known as aerials, are a crucial component in the field of wireless communications.
There are two main types of Wi-Fi antennas: directional antennas, which transmit and receive radio waves from a specific direction, and omnidirectional antennas, which transmit and receive radio waves in all directions without a fixed focus.
Directional Antenna
A directional antenna is designed to focus its radio wave transmission and reception in a specific direction, enhancing signal strength and reach in that area.
Omnidirectional Antenna
An omnidirectional antenna, in contrast, broadcasts and receives signals in a 360-degree pattern, providing broad coverage but with generally weaker signal strength compared to directional antennas.
Wi-Fi antennas are available for both indoor and outdoor use, with different configurations based on the intended environment.
Indoor Wi-Fi antennas are typically connected directly to the access point or through a conversion cable. Outdoor Wi-Fi antennas, on the other hand, are connected via a coaxial cable to a conversion cable linked to the access point. This setup is chosen to minimize high-frequency transmission loss and for installation ease, relay convenience, and the ability to carry direct current.
Uses of Wi-Fi Antennas
With the increasing spread of new communication standards, the demand for Wi-Fi antennas has grown, finding applications across various industries. However, due to the nature of Wi-Fi signals, which can be absorbed by water, metals, and other substances, communication can be unstable in certain environments.
For instance, on ships, where the interior is metallic, Wi-Fi signals struggle to penetrate, posing challenges in building wireless or wired LAN environments. To address this, “Power Line Communication (PLC)” is emerging as a solution. PLC uses existing power lines for data communication, allowing for the creation of a network environment by connecting PLC equipment to power outlets and linking access points and routers to PLC devices in different rooms.
Principle of Wi-Fi Antennas
Wi-Fi antennas come in various shapes and types, such as sector, flat, and omnidirectional antennas. These antennas are designed to handle specific frequency bands and standards, including the 2.4GHz and 5GHz bands commonly used in wireless LANs. For instance, sector antennas incorporate phase shifters and horizontal elements for transmitting and receiving various radio waves and are often protected by a radome to shield against external elements like rain and wind.
The different Wi-Fi standards, such as IEEE 802.11b/g (2.4GHz band) and IEEE 802.11a/ac (5GHz band), along with dual-band standards like IEEE 802.11n (Wi-Fi 4) and IEEE 802.11ax (Wi-Fi 6), determine the communication speed and characteristics. Wi-Fi antennas play a vital role in ensuring stable communication for these standards.