The purpose of using a radome is to:
① Protect the antenna system from wind, rain, ice, snow, sand and solar radiation, etc., so that the working performance of the antenna system is relatively stable and reliable, and at the same time reduce the wear, corrosion and aging of the antenna system, and prolong the service life.
② Eliminate the wind load and wind torque, reduce the driving power of the rotating antenna, reduce the weight of the mechanical structure, reduce the inertia, and increase the natural frequency.
③ Relevant equipment and personnel can work in the hood and are not affected by the external environment, so as to improve the use efficiency of equipment and improve the working conditions of operators.
④ For high-speed flying aircraft, the radome can solve the problems caused by high temperature, aerodynamic load and other loads to the antenna.
However, the radome is an obstacle in front of the antenna, which will absorb and reflect the radiated waves of the antenna, change the free space energy distribution of the antenna, and affect the electrical performance of the antenna to a certain extent.
The reason is:
①The reflection of the radome wall and the diffraction of the uneven part will cause the electrical axis of the main lobe of the antenna to shift, resulting in aiming error;
②The absorption and reflection of high-frequency energy by the radome will cause transmission loss, which will affect the antenna gain (increase the system noise temperature when receiving);
③The antenna lobe distortion caused by the radome will change the antenna main lobe width, increase the null depth and increase the side lobe level;
Secondly, the radome increases the engineering cost. Antennas on aircraft are generally equipped with radomes, while ground radomes have not been widely used.
Folding edit this paragraph radome classification
①From the use, it is divided into two categories: aviation type and ground (including shipborne) type.
②According to the incident angle of the radiated wave from the antenna, it is divided into a vertical incident radome and a large incident angle radome. The angle between the radiation wave ray and the normal to the cover wall is the incident angle. An incident angle less than 30° is called a vertical incident radome. When the antenna scans to any position in the cover, the variation range of the incident angle is relatively large (from 0 to 75 or more), which is called a large incident angle radome. The electrical performance of the latter is much lower than that of the former.
③ According to the cross-sectional shape of the radome wall, the radome is divided into three types: uniform single-wall structure, sandwich structure and space skeleton structure.
④According to the forming method of the radome, the ground radome is divided into two types: inflatable cover and rigid cover.