How to choose a frequency band for drones

In many cases, the diffraction or scattering capabilities we pursue when choosing UAVs are not practical for our requirements for real-time transmission and control. Therefore, the specific frequency is not certain. It mainly depends on the individual's greatest interest in a certain product and personal preference, but the only thing to note is that the possibility of interference should be avoided as much as possible.

The two frequencies of 2.4G and 1.2G are not unavailable if you know that the specific frequency of the image transmission and the frequency point of the control are not conflicting, but if you are not clear, the risk is still relatively large. The closer the frequency, the interference will occur. The greater the possibility.

The 1.2G frequency band does not have an open frequency band. It only provides the legal use rights for radio enthusiasts who have obtained qualification certificates. In a sense, unauthorized use may be illegal.

In the 433M frequency band, many friends choose equipment in this frequency band in order to pursue the so-called penetration (diffraction). This is an open frequency band and it is available, but one thing is very fatal, that is, the signal interference is large. Because of this frequency band The frequency is not high, the cost is low, the antenna is small and easy to miniaturize, and it is portable and installed, so it has become the most crowded frequency band in amateur radio.

summary

Radio waves are invisible and intangible, so people often ignore its existence, because the radio equipment we use daily is protected by laws and regulations and will not be interfered. The concept of interference is often not in my mind. If you are in a big city Here, using the 433M frequency band, it is tantamount to dancing on the tip of a knife. The small power of the image transmission is really pitiful in front of the powerful tens of watts. In the case of interference, it is not enough to explain the problem if the interview machine is normal on the ground. When the distance is increased, the consequences will be serious, because one phenomenon will be suppressed, such as driving on the road and listening to the radio. The two stations have the same frequency, and then the radio will receive alternately according to the strength of the two-phase signal between the two stations, unless you really confirm that there is no interference source there.

Finally, my personal opinion is more biased towards higher frequency image transmission, such as 5.8G. Countries in this frequency band have allocated an open amateur frequency band. In addition, high frequency antennas can be more miniaturized. At present, there are few equipment working at 5.8G. This frequency band is relatively relatively small. Pure static, less interference, but there are advantages and disadvantages. The higher the frequency, the higher the cost of electronic components, the higher the accuracy requirements for antennas, etc., and the easier it is to generate heat. It is more sensitive to the permeation magnet near the transmitter than the low frequency. More difficult etc.


Open operating frequency band (only list the common and commonly used video transmission) 430M-440M 2.4G-2.4835G 5.15M-5.35M and 5.725G-5.850GHZ

Radio frequency also belongs to the classification of national resources, and is protected and restricted by national laws, except for open frequency bands that can be used within the specified range. If you use radio equipment too frequently, you should learn more about national and local laws and regulations to avoid illegal consequences.

100 KM long range Video & Data and telemetry for UAV

100 KM long range Video & Data and telemetry for UAV

100 KM long range Video & Data and telemetry for UAV  Infofly long-distance image, data transmission, and remote control integrated data link products provide highly reliable communication connections for industrial-grade unmanned systems. Infofly data link products use unique link enhancement technology, which has strong anti-interference performance, stable signal, rich interface types, and excellent electromagnetic compatibility, which can improve the stability and reliability of information transmission of unmanned systems at long distances and maneuvering attitudes. . The product can provide 6Mbps data bandwidth, the longest communication distance is 100 kilometers, supports 1080P HD video transmission, and the image delay is within 280ms. The data link product also provides remote control coach interface, RS232 interface, etc. The airborne end can replace the remote control receiver to directly output the remote control signal, the remote control signal delay is within 40ms, and can be widely used in high-definition image transmission, real-time data interaction and other unmanned System application scenarios.

The InfoFly-SDI data link has a built-in industrial-grade high-performance H.264 image encoder, supports SDI interface video input, realizes three-in-one image transmission, data transmission, and remote control. The ground end outputs a video stream through a network interface and uses computer software to decode The decoding software has local storage and forwarding functions. The end-to-end image delay is at least 250ms.

Features
Working in L, S band
Broadband transmission, air rate 10Mbps
Communication link establishment/recovery time is less than 10ms
Reliable communication and strong anti-interference ability
Excellent electromagnetic compatibility, no interference to GPS, pod and gimbal
Transmission distances of 3, 5, 10, 20, 40 kilometers and more than 50 kilometers can be selected (under visual conditions)
With 1 1080P60 SDI HD image, 4 digital transmission, 2 remote control interface
1 independent PWM channel output on the airborne end, can be used for signal control such as drop and lighting
The ground side adopts software decoding, and the decoding software has local storage and forwarding functions
Optimized transmission of 1080P high-definition video stream with minimum end-to-end delay of 250ms
Can realize point-to-point, point-to-multipoint, relay networking applications
Cold start time 5 seconds.

typical application
When users choose SDI interface pods, they need to choose InfoFly-SDI data link radio. InfoFly-SDI has a built-in high-performance industrial-grade SDI interface encoder that outputs H.264 code stream.

Figure 2. Typical application of InfoFly-SDI data link
Airborne end: SDI interface connects to pod or PTZ camera; COM1 interface connects to flight control data transmission interface for data transmission between flight control and ground station; SBUS1 interface connects to flight control for manual remote control flight; SBUS2 interface Connect PTZ to control PTZ. If the gimbal supports data transmission port control, InfoFly-SDI has 4 data transmission interfaces, and it can also support the gimbal control through the data transmission port.
Ground end: LAN port connects to the computer, receives H.264 high-definition image code stream and performs software decoding. The decoding software has functions such as local storage and network forwarding. The COM1 port is used to connect the flight control ground station to complete the telemetry remote control data transmission; the COM2 port can be used to control the gimbal and pan/tilt; the PPM1 remote control interface is connected to the first remote control through the trainer line to control the flight; the PPM2 remote control interface is passed The trainer line is connected to a second remote control for controlling pods or other loads. If the PTZ on the airborne end is controlled by a digital transmission interface, the ground needs to connect the PTZ control box to the corresponding digital transmission interface.