English 
Views: 62 Author: Site Editor Publish Time: 2019-08-09 Origin: Site
UAV video transmitters is often applied to drones that require mobile video transmission. Nowadays, drones fly farther, which requires higher performance of drone video transmitters.This article explains several common factors affecting transmission distance, hope it will help you to learn how to improve transmitters' performance.
Here is the content list
1. What is wireless transmission?
2. UAV video transmitter
3. The factors affecting the distance of UAV video transmitter
4. Suggestions
5. Summary
Wireless transmission does not require the arrangement of cables, but uses electromagnetic waves to transmit signals such as video, sound, and data.
Common forms of wireless transmission include: analog transmission, data transmission, CDMA(Code Division Multiple Access), 4G, digital microwave (mostly spread spectrum microwave), WLAN (Wireless Network), COFDM (Orthogonal frequency Division Multiplexing) and so on.
Auto pilot, video transmitter and data transmitter are the most important three parts on a drone. Among them, video transmitter plays as “eyes” of a drone, it can transmit video from air to ground in time, letting you see what drones see.
UAV video transmitter is an important applying of digital microwave. In practical applications, due to the characteristics of microwaves, there are some factors that will affect the transmission performance.
For the wireless video transmission of different frequency bands, there is one thing in common, the distance transmitted under the line of sight condition is the farthest.Usually the low-frequency equipment has good diffraction performance, so that its transmission effect is better than that of high-frequency equipment within a certain range.
The signal will be greatly attenuated after passing through obstacles such as reinforced concrete walls, steel plates, trees, and metal products. The denser the obstacles, especially the metal obstacles, the greater the impact on the wireless communication distance.
If the environment is humid(especially in rainy and snowy weather), the frequency receiving sensitivity will be reduced, as well as the communication distance. Moreover, most of drones video transmitters have large power consumption, they needs physical heat dissipation.For this reason ,few of them can be waterproof. If it is used in rainy or snowy days, it is possible to burn out the equipment if the water drops into the casing.
The antenna is very important for the transmitters.Under the same conditions, if the antenna is selected well, it can even increase the distance of the wireless image by 20% to 30%. The appearance mode, elevation performance and anti-interference performance of the antenna will have an impact on the signal receiving effect.
The drone often equips with radio control, digital transmission, GPS and other radio stations. The electromagnetic environment on the fuselage body with limited volume is very complicated, which will cause interference between different radio stations.
Compared with ground robots, drones require more stringent use of the environment. Users are advised to avoid some obstacles as much as possible when fly a drone. The unobstructed flatness is the farthest geographical communication distance. Regardless of whether the drone is used for low-frequency or high-frequency transmission, the requirements for environmental visibility are the sameif the distance is more than 10km.
Do not use transmitters in bad weather conditions. Waterproof preparation should also be done in light rain.
The maintenance of the devices should also be carried out in a dry environment.
The appropriate antenna should be selected according to the shape and weight of the drone. For products that are long-distance routed, directional antennas with trackers can be configured; for short-range transmissions, omnidirectional antennas are suggested.
In addition, under the same conditions, the higher the height of the antenna from the ground, the farther the communication distance is.
Minimize the installed radio stations on the drone, and give limited physical space to the necessary radio stations, such as flight control, digital transmission and picture transmission, and the frequencies between various radio stations should be effectively spaced apart, otherwise it will cause the same Frequency interference.
There are many factors that affect the transmission distance of the video transmitters. Because the drone is a whole system rather than a single individual, it needs different parts to work together. Therefore, patience is also necessary. When testing a drone, you should do more tests to continuously optimize the position between different stations on the drone to achieve the best results.
