What is the wireless bridge antenna for? Why an antenna

2019-08-22 17:00

When we introduce products to customers, we always mention the word antenna. As anyone who has ever been in touch with a wireless bridge will know, wireless Bridges all have antennas, just divided into a built-in antenna and an external antenna. The built-in antenna is often mistaken for no antenna because it cannot be seen. Many customers will ask is with the antenna is good or not with the antenna, today, small make up here under the official reply, no matter which kind of wireless bridge, there is an antenna, just the difference between the built-in and external.


Wireless bridge signal transmission principle: rf signal power output by the transmitting end of the bridge is transmitted to the antenna through the feeder (cable), and then radiated out by the antenna in the form of electromagnetic wave. When the electromagnetic wave arrives at the receiving site, it is received by the antenna and sent to the receiving end of the bridge through the feeder. It can be seen that the antenna is the transmitting device of the wireless bridge signal. Without the antenna, the signal of the wireless bridge cannot be transmitted, so there is no radio communication. In other words, we often say that the wireless bridge transmission is actually transmitted through the antenna.


And there are many different types of antennas, depending on the frequency of the bridge, different distances, different environments, different occasions to use different antennas. According to the installation mode, there is a built-in antenna and an external antenna; According to the direction of the distinction, there are directional antenna and omnidirectional antenna; By frequency, there are 2.4g antenna and 5.8g antenna; By shape, there are yagi antenna, flat antenna, pot antenna... With so many antennas, will it be difficult to choose?


Internal antenna and external antenna


1. Built-in antenna


Built-in antenna refers to the antenna integration wireless bridge, small size, easy to install, generally used in the short-range wireless transmission system, generally can use the built-in antenna within 10 kilometers.


2. External antenna


External antenna is generally large, if the transmission distance is relatively far, such as more than 10 kilometers, it is recommended to use a high-gain external antenna. The remote transmission of external antenna is generally point-to-point transmission. Because of the distance, the Angle is relatively small. Except for omnidirectional antennas.


Directional antenna and omnidirectional antenna


1. Directional antenna


It is generally used in environments with long transmission distance, small coverage, high target density and high frequency utilization. Directional antenna signals can only be transmitted forward. The purpose of using directional transmitting antenna is to increase the effective utilization rate of radiated power, increase the confidentiality and increase the anti-interference ability.


2. Omnidirectional antenna


Performance in horizontal direction chart for 360 ° uniform radiation, radiation scope is more like an apple, zero omnidirectional, normally used in the transmission distance, large coverage of the environment. Omnidirectional antenna signals are transmitted in all directions, which are cheap and have relatively small gain, generally below 12dBi.


Three, 2.4G antenna and 5.8G antenna


The frequency choice is very simple, is the wireless bridge frequency is what to choose the corresponding antenna. If the wireless bridge is 2.4g, choose a 2.4g antenna. If the wireless bridge is 5.8g, select the 5.8g antenna. Never use a 2.4g antenna on a 5.8g bridge or a 5.8g antenna on a 2.4g bridge, which can cause signal transmission failure.


Looking at the text, the antenna looks a little complicated. It's actually pretty simple. As long as you explain your specific situation to the Ryan staff, we will help you configure. You don't have to make your own choices.