Against the backdrop of the rapid development of the global low-altitude economy, the civilian unmanned aerial vehicle (UAV) industry is facing a historic development opportunity. This trend indicates that the application of UAV technology will expand comprehensively from a single consumer field to diversified and large-scale commercial applications. The relationship between civilian UAV systems and RF isolators mainly lies in communication link protection and signal isolation. As a key RF component, isolators directly affect the communication reliability and anti-interference capability of UAVs.
The core connection is as follows:
1.Functional Principle: Enabling Unidirectional Signal Transmission
(1) Preventing Mutual Interference of Transmit and Receive Signals
The isolator forces unidirectional transmission of signals from transmitter to antenna through non-reciprocal characteristics, while blocking antenna reflected signals from returning to the transmitter. In UAV communication links (e.g. 2.4GHz remote control or 5.8GHz mapping), it can avoid the reverse surge of transmit power into the receiver, which can lead to circuit damage or data transmission interruption.
(2) Absorb reflected energy and protect sensitive devices
When the antenna has an impedance mismatch due to environmental interference (e.g., urban electromagnetic noise), the matching load inside the isolator absorbs the reflected waves and prevents the power amplifier from burning out due to high VSWR (VSWR).
2.Main application scenarios
(1) Multi-band communication system protection
Frequency bands commonly used by civilian UAVs include:
- 840.5-845MHz (Remote Control, Uplink)
- 1430-1444MHz (Telemetry, Downlink)
- 2.4GHz/5.8GHz (Backup Frequency Band)
The isolator should cover the above frequency bands and be deployed in each RF front-end module to ensure that the transceiver signals of different frequency bands do not interfere with each other.
(2) High-power module security
- High-definition mapping system: 5.8GHz band needs stable output power, and the isolator can absorb antenna reflection energy and protect the life of the power amplifier.
- Anti-drone jamming equipment: 100W class RF amplifier (e.g. GaN module) relies on isolators to prevent strong reflected signals from damaging the circuit.
3.Technical and selection requirements
Key parameters of UAS isolator requirements:
- Frequency range: to adapt to multi-band communication requirements.
- Isolation: to determine the reverse signal blocking capacity.
- Insertion loss: signal transmission attenuation.
- Power capacity: withstand high power transmission scenarios.
Selection Example:
Coaxial Isolator–UIYCI1522A series
- Frequency Range: 4.4-7.2GHz, Duty Cycle: 25% (Covering mainstream 5.8GHz UAV mapping band)
- Isolation: ≥23dB
- Insertion loss: ≤0.3dB (very low signal attenuation)
- Power capacity: 60W (meet the demand of HD mapping)
- Size: 15×22.5×13.8mm
Coaxial design, small size and light weight. Suitable for industrial-grade UAVs !
Drop in Isolator–UIYDI1220A series
- Frequency range: 4.0-8.0GHz, 25% duty cycle (covers mainstream 5.8 GHz UAV mapping band)
- Isolation: ≥23dB
- Insertion loss: ≤ 0.3dB (very low signal attenuation)
- Power capacity: 60W (to meet the demand of HD mapping)
- Size: 12×20×8mm
Ultra-thin design, suitable for lightweight UAVs !
Drop in Isolator–UIYDI1212B series
- Frequency range: 0.7 to 6GHz, Duty cycle 30%.
- Isolation: ≥23dB
- Insertion Loss: ≤0.3dB (very low signal attenuation)
- Power Capacity: 60W/20W
- Size: 12.7×12.7x8mm
Supports full-band customisation, powerful cost advantage!
4.Future Development: Miniaturisation and Integration
(1) Popularisation of Surface Mounted (SMT) Devices
The new isolators can be directly soldered to PCBs, replacing the traditional coaxial connectors, significantly reducing weight and improving heat dissipation efficiency.
Surface Mount Isolator–UIYSI12A series
- Frequency Range: 0.7 to 10GHz, Duty Cycle 20%
- Isolation: ≥23dB
- Insertion loss: ≤0.3dB (very low signal attenuation)
- Power Capacity: Reflected Power Tolerance of 10W, effectively preventing signal reflection from damaging the circuit.
- Dimensions: 12.7×8mm max
Surface Mount Isolator–UIYSI10A series
- Frequency Range: 2.4-6.0GHz, Duty Cycle 20%
- Isolation: ≥23 dB
- Insertion loss: ≤0.3dB (very low signal attenuation)
- Power Capacity: Reflected Power Tolerance of 10W, effectively preventing signal reflection from damaging the circuit.
- Dimensions: 9.8x7mm max
(2) Modular integrated design
Isolator and power amplifier, filter and other integrated RF module, reducing system complexity and improving the stability of communication links.
Conclusion: RF Isolator is the invisible guardian of civil UAV communication system.