What is the working frequency of the radar?

In practical application, according to the performance requirements and implementation conditions of radar, most radars work in the microwave band of 1 ~ 15 GHz. Below the frequency of 1GHz, due to the frequency band occupied by communication and television, the frequency spectrum is crowded, which is rarely used by general radars, and only a few long-range radars and over-the-horizon radars use this frequency band.

When the frequency is higher than 15GHz, water molecules in the air are seriously absorbed; When the frequency is higher than 30GHz, the absorption of oxygen molecules and water molecules increases sharply in some areas. With the increase of frequency, antenna processing is difficult, noise inside and outside the receiver increases, and it is difficult to increase transmitter power.

Therefore, these frequency bands are rarely used by general radars, and only some high-resolution radars and radars working in outer space use such high frequencies, such as millimeter-wave radars and lidar.

Working principle of radar

Radar functions like eyes and ears. Of course, it is no longer a masterpiece of nature, and its information carrier is radio waves. In fact, visible light and radio waves are essentially the same thing, both electromagnetic waves, and the propagation speed in vacuum is the speed of light C, the difference lies in their respective frequencies and wavelengths.

Its principle is that the transmitter of radar equipment emits electromagnetic wave energy to a certain direction in space through an antenna, and the object in this direction reflects the electromagnetic wave it encounters; After receiving this reflected wave, the radar antenna sends it to the receiving equipment for processing, and extracts some information of the object (the distance from the target object to the radar, the change rate of distance or radial speed, azimuth, altitude, etc.). ).