Microwave antenna of Contents
Microwave antenna
Transmitting or receiving antennas working in meter wave, centimeter wave, millimeter wave and other bands are collectively referred to as microwave antennas. Microwaves are mainly propagated by space waves. In order to increase the communication distance, the antenna is erected higher. Among microwave antennas, parabolic antennas, horn parabolic antennas, horn antennas, lens antennas, slotted antennas, dielectric antennas, and periscope antennas are widely used.
Classification of microwave antennas
The microwave antenna is divided into two types according to the installation method: hanging antenna and base antenna.
According to electrical characteristics, there are two types of microwave antennas: standard antennas and high-performance antennas.
The difference between standard antennas and high-performance antennas is that the front-to-back ratio of high-performance antennas is larger than that of standard antennas, generally more than 10dB.
Installation of microwave antenna
Due to the influence of terrain and environment, the electromagnetic waves received by the antenna are effective direct waves, reflected and diffracted waves, or their superposition. The result determines the magnitude and phase of the field strength at the receiving point, and directly affects the application effect of the antenna. . Therefore, there are certain requirements for the installation of the antenna, and the following aspects should usually be paid attention to when choosing the installation location of the antenna.
(1) The transmitting or receiving direction of the antenna should avoid obstacles as much as possible: such as tall buildings such as buildings, iron towers, bridges, etc., to avoid multipath interference that can easily affect communication due to electromagnetic wave reflection and refraction.
(2) The antenna installation site should be as far away as possible from interference sources: such as high-voltage lines, aircraft routes, densely populated areas, highways, etc., to reduce or avoid possible interference to microwave communication; also minimize the interference of microwave communication systems to the outside world.
(3) The antenna should be set up at a nearby high point as far as possible: according to the characteristics of microwave transmission, this can increase the communication distance and obtain relatively good communication quality.
(4) If several pairs of antennas work on the same tower, special attention should be paid to the left and right and up and down spacing and operating frequency between them to prevent mutual coupling from affecting system performance.