In the complex system of a drone, the antenna acts like its "nerve endings," undertaking the core functions of signal reception and transmission. The frequency adopted by the antenna is a key parameter that directly determines the communication quality, transmission distance, and applicable scenarios of the drone. With the in-depth penetration of drone technology in fields such as consumer entertainment, industrial surveying and mapping, and emergency rescue, diverse mission requirements have spawned the refined use of multiple frequencies. The following is a systematic analysis of the common frequencies of drone antennas and their technical characteristics.
I. 840.5-845MHz Frequency Band
This frequency band serves as the core for the uplink remote control link of civil drones. Among them, the 841-845MHz range can integrate both uplink remote control and downlink telemetry functions through time-division multiplexing technology. In terms of radio wave propagation, its longer wavelength endows the signal with excellent diffraction capability, which can effectively avoid shielding from obstacles like trees and low-rise buildings, ensuring communication stability in complex terrains. In practical applications, low-altitude operational drones with strict flight safety requirements (such as power inspection drones) generally adopt this frequency band. Reliable command transmission reduces the risk of loss of control, making it particularly suitable for operations in urban building clusters or hilly areas.
II. 1430-1444MHz Frequency Band
As the dedicated frequency band for downlink data transmission of civil drones, the 1430-1444MHz frequency band features refined functional division: the 1430-1438MHz segment is designated for video transmission of police drones and helicopters, meeting the demand for real-time transmission of high-definition images in police operations due to its stable signal characteristics; the 1438-1444MHz segment caters to industrial-grade drones, undertaking the downlink transmission of information such as flight parameters and surveying data. In large-scale engineering surveying projects, this frequency band can efficiently transmit terrain data with centimeter-level accuracy, providing complete data support for subsequent modeling and analysis. Its transmission efficiency and stability are particularly prominent in long-endurance operations.
III. 2.4GHz Frequency Band (2400-2476MHz)
The 2.4GHz frequency band has become the mainstream choice for consumer drones due to its technical maturity and cost advantages. Its core advantages are as follows: sharing frequency band resources with civilian devices like Wi-Fi and Bluetooth significantly reduces the R&D and manufacturing costs of communication modules; its shorter wavelength enables a certain degree of diffraction in urban environments, allowing it to cope with small obstacles such as trees and telephone poles. However, the openness of this frequency band also brings notable drawbacks – equipment-dense areas (such as large exhibition venues) are prone to electromagnetic interference, which may reduce communication distance by over 30% or even cause signal interruption. Nevertheless, in scenarios like small-scale aerial photography and home entertainment, the 2.4GHz frequency band remains the most cost-effective option.
IV. 5.8GHz Frequency Band (5725-5829MHz)
The 5.8GHz frequency band has become the preferred choice for professional-grade drones due to its broadband advantage. Its 104MHz bandwidth can support the stable transmission of 4K/60fps high-definition video, meeting the needs of high-quality image transmission in applications such as film aerial photography and thermal imaging detection of power lines. Compared with the 2.4GHz frequency band, this band has lower equipment density, with electromagnetic interference reduced by over 60%, significantly improving communication stability in open areas. However, it has an obvious drawback: the millimeter-wave nature leads to rapid signal attenuation, and transmission distance drops sharply when passing through large buildings or mountains. Therefore, it is more suitable for open scenarios such as plain crop protection and maritime patrols.
V. Auxiliary Function Frequency Bands
Obstacle Avoidance and Radar Frequency Bands
The obstacle avoidance system of civil drones mainly utilizes 24-24.25GHz frequency band micro-power radar. Radar waves in this band can penetrate interfering media such as rain, fog, and sand, enabling accurate detection of obstacles within 0.5-50 meters and providing reliable data for autonomous obstacle avoidance algorithms. In high-end models, 60GHz and 77GHz frequency band radars are used to enhance detection accuracy. For instance, Narey Technology's NRA24 radar altimeter can maintain a measurement accuracy of ±0.02 meters even in complex terrains.
Satellite Navigation Frequency Bands
Drone positioning and navigation rely on multi-system satellite signals: the L1 (1575.42MHz), L2 (1227.60MHz), and L5 (1176.45MHz) bands of GPS, combined with the B1 (1561.098MHz), B2 (1207.14MHz), and B3 (1268.52MHz) bands of Beidou, form a complementary system. Through multi-frequency fusion calculation, positioning errors can be controlled within 1 meter, and navigation stability can be maintained in complex environments such as canyons and urban canyons.
VI. Special Application Frequency Bands
433MHz and 915MHz Frequency Bands
These two frequency bands are ideal for low-speed data transmission due to their long-wavelength characteristics. The SiK Radio module based on the MavLink protocol can achieve command transmission over 10 kilometers in complex terrains like mountainous areas via the 433MHz/915MHz bands. Devices such as DragonLink remote controllers, when using this frequency band, have 50% better anti-interference capability compared to 2.4GHz devices. However, the transmission rate of approximately 100kbps limits it to transmitting flight commands and status parameters, making it unable to carry video signals.
700MHz Frequency Band
Known as the "golden frequency band for communication," 700MHz holds unique value in emergency communication. When China Broadcasting's 5G emergency communication drone is equipped with a base station of this frequency band, it can achieve signal coverage of 72 square kilometers at an altitude of 4000 meters, with RSRP (Reference Signal Received Power) stable at -92dBm, which is 2-3 times more efficient in coverage than conventional schemes. During earthquake rescue, the "Wing Loong" drone quickly established a temporary communication network using the 700MHz band, ensuring smooth voice and SMS services in the rescue area.
5G Fusion Frequency Bands
The 26GHz millimeter-wave band, with a transmission rate of 10Gbps, has become the core carrier for low-altitude drone communication. In tests at the Beijing Yanqing Drone Industrial Park, this band enabled centimeter-level positioning and real-time data interaction for 100 drones. The 4.9GHz band, working in conjunction, addresses the penetration limitation of millimeter waves with its wide coverage. The collaborative sensing network formed by the two can meet both high-speed image transmission and long-distance control needs, providing technical support for urban drone logistics.
Remote Sensing Imaging Frequency Bands
In remote sensing detection, bands such as Ku (12-18GHz), X (8-12GHz), and L (1-2GHz) each have their strengths: the Ku band is suitable for high-resolution terrain mapping, the X band can penetrate cloud layers to obtain surface information, and the L band excels in vegetation monitoring. Zhanjiang Technology's (Ku+X) dual-band MiniSAR system can provide both centimeter-level terrain data and surface deformation information through multi-band data fusion, significantly improving the accuracy of geological disaster monitoring.
The selection of drone frequencies is essentially an accurate matching of technical characteristics and scenario requirements: short-wavelength bands prioritize transmission efficiency, long-wavelength bands focus on coverage capability, and millimeter-wave bands emphasize detection accuracy. With the development of 6G technology and terahertz bands, drone communication will realize full-frequency collaboration in "space-air-ground integration" in the future, opening up broader prospects for industrial applications.
