8 June 2011
Using the Correct Antenna to avoid Polarisation Mismatch between UAV and Ground Station to Ensure Stable Communication Links
Ensuring communication links are maintained between the UAV and ground control station can be challenging as the link budget is dependent on the relative polarization alignment. When selecting the antenna system, using the correct polarization configuration is essential: “Avoiding Polarisation Mismatch”.
With linear polarization on the remote platform (UAV), as it banks the signal can drop due to polarisation mismatch. Circular polarisation at one or both ends will maintain the link, but antennas with circular polarisation sometimes have a large diameter and may not be suitable for mounting on an airborne platform.
The preferred option is to have linear polarisation (usually vertical) on the UAV for wide angle coverage, and circular polarisation on the ground. As long as a 3dB reduction is allowed for in the link budget in calculations to work out platform range, the antenna system will work at all angles as orientation of the UAV becomes irrelevant.
Antennas with all types of polarization and power rating are available, including multi sector antennas that have both sector and overhead coverage for ground control centres, and omni-directional and directional blade style antennas for Unmanned Vehicles.
For advice on the right antenna combination, please contact us direct to discuss your requirements in more detail.