Everyone is familiar with TV antennas. I remember that old-fashioned black-and-white TVs were pole-mounted TV antennas that had their own antennas and were later developed outdoors. But so far, TV antenna technology has become more mature. Today's antennas can greatly meet our daily needs. However, many people buy antennas home but don’t know the antennas. They don’t know the working principle of the antennas, and they have no idea about the installation location. Don't understand. Today, I will introduce you to a detailed explanation about the TV antenna, hoping to help you.
1. The working principle and function of antenna
Antenna is an indispensable part of wireless communication, and its basic function is to radiate and receive radio waves. When transmitting, the high-frequency current is converted into electromagnetic waves; when receiving, the electric wave is converted into high-frequency current.
2. Classification of antennas
There are many types of antennas, and there are mainly the following classification methods: According to their purpose, they can be divided into base station antennas and mobile portable antennas. According to the working frequency band, they can be divided into ultra-long wave, long wave, medium wave, short wave, Ultrashort wave and microwave; according to their direction can be divided into omnidirectional and directional antennas.
Three, the gain of the antenna
Gain is one of the main indicators of the antenna. It is the product of the directivity coefficient and the efficiency, and it is the performance of the antenna radiation or the size of the received radio waves. The choice of gain depends on the requirements of the system design for the radio wave coverage area. Simply put, under the same conditions, the higher the gain, the longer the radio wave propagation distance. Generally, base station antennas use high gain antennas, and mobile station antennas use low gains. antenna.
Fourth, how to choose an antenna
Antenna is an important part of the communication system, and its performance directly affects the indicators of the communication system, and the user must first pay attention to its performance when choosing an antenna. Specifically, there are two aspects, the first choice of antenna type; the second choice of electrical performance of the antenna. The significance of selecting the antenna type is: whether the pattern of the selected antenna meets the requirements of radio wave coverage in the system design; the requirements for selecting the electrical performance of the antenna are: whether the electrical indicators such as the frequency bandwidth, gain, and rated power of the antenna meet the system design requirements. Therefore, it is best for users to contact the manufacturer for advice when choosing an antenna.