From：Zhaoqing Xiangjiasheng Technology Co., Ltd Release time：2020-11-21
Antennas are mainly divided into three types: directional antennas, omnidirectional antennas and sector antennas. The main difference is the beam width.
Basically, WiFi networks can use two different frequency bands. 2.4 GHz and 5 GHz frequency bands. The 2.4 GHz frequency band compliant with IEEE802.11b/g/n is still the current standard. The 5 GHz frequency band that conforms to the IEEE802.11a/n/ac standard is more susceptible to interference, but provides more channels than the 2.4 GHz frequency band, so the frequency of use is getting higher and higher. In addition, there may be extremely high data rates here.
Connecting various devices via WiFi has become the standard, and almost no one wants to solve the annoying cable mess. However, in order to establish and maintain a stable WiFi connection, several factors must be considered. Especially in a narrow space, there are many confounding factors that will severely limit the approximately 100-meter range promised by standard routers. Radio signals are mainly interfered by obstacles such as furniture and walls, and are therefore reduced. Metal objects redirect the signal so that the signal may not reach the device at all or only be greatly attenuated at the device. Although the signal strength and transmission security can be improved from the perspective of routers, bridging larger areas usually cannot avoid the use of external resources.
When do I need a WiFi antenna?
Whenever you want to increase the range of a WiFi network or amplify the signal in a specific direction, you can use a WiFi antenna. Most routers are equipped with antennas when they leave the factory, which can then be upgraded to higher-quality WiFi antennas to improve range or signal strength or precise alignment. A high-quality antenna can be connected to the router via a cable for precise positioning. However, the cable should not be too long, as it will reduce the signal strength again. Basically, there are three different types of WiFi antennas: directional antennas, omnidirectional antennas and sector antennas. By default, most networks are in the 2.4GHz band, and for special networks, 5GHz can be used. The antenna must always be adjusted to the frequency band used.
2.4GHz directional antenna
The directional antenna focuses the signal and amplifies it to the direction. Directional antennas are always useful when you want to receive signals at greater distances and at a certain point, such as through a single device or hotspot that can further distribute the signal. The higher the dBi number of the WiFi directional antenna, the greater its range. The size of the signal opening angle indicates the transmission strength of the signal. The smaller the angle, the more concentrated the signal, and the stronger the signal to the destination. 2.4 GHz directional antennas are used in WiFi networks in the 2.4 GHz frequency band.
2.4GHz omnidirectional antenna
Unlike directional antennas, omnidirectional antennas transmit in all directions and cover a larger area. Most importantly, it is suitable for base stations such as routers or access points, which are usually used for these purposes. The general range of an omnidirectional antenna is given in dBi, the higher the dBi number, the larger the range. However, even with omnidirectional antennas, it should be noted that the free area range is significantly higher than when a closed room or when many obstacles interfere with the signal. Therefore, it is likely that the range in different directions will be different due to certain circumstances. The 2.4 GHz omnidirectional antenna is designed for WiFi networks in the 2.4 GHz band.
2.4GHz sector antenna
Sector antenna is a hybrid of directional antenna and omnidirectional antenna. The opening angle is smaller than the omnidirectional antenna, and the signal strength is higher, but of course not as high as the special directional antenna. It is usually used when WiFi signals are to be provided to a large area (for example, several buildings, campgrounds, or event venues). In order to obtain the 360° coverage of an omnidirectional antenna, several sector antennas with different directions can be used. The signal range is represented by the dBi value. The higher the value, the farther the sector antenna can transmit. For standard WiFi networks, use 2.4 GHz antennas.
5GHz directional antenna
The directional antenna concentrates the signal in a certain direction, so it can reach a higher range with a smaller area coverage. 5 GHz directional antennas are used in networks in the 5 GHz band, for example to establish connections with access points.
5GHz omnidirectional antenna
The range of the omnidirectional antenna is smaller than that of the directional antenna, but the coverage area is larger, so it is very common in the family. In the 5 GHz frequency band, they are mainly used in office buildings, because at this frequency, their susceptibility to interference and range are slightly lower than the usual 2.4 GHz frequency band.
5GHz sector antenna
The sector antenna is a useful combination of omnidirectional and directional antennas, which not only has good area coverage, but also has a wide signal opening angle (maximum 180°) and good coverage. Especially for large open spaces, they are the best choice. 5 GHz sector antennas are used in networks in the 5 GHz band.