Feasibility study on replacement of coaxial cables with optical fiber links in UAVs

Aircrafts (Manned or Unmanned) need communication links that are light weight, immune to electromagnetic interference, high bandwidth and reliable for onboard communication. Conventionally the antennas and respective Line replaceable units use coaxial cables for interconnection that are complex and suffers from Electromagnetic Interference problems. Using optical fiber for both Radio Frequency and data level signal communication will have the inherent advantages viz. less weight, negligible loss, compact solution, less complex, no electromagnetic interference/ compatibility problem etc. The conventional coaxial links based solutions are not able to satisfy the increased data handling requirements of today's advanced aircrafts. The realization of this scenario will need more number of coaxial cables that are bulky resulting in a complex architecture. It is therefore proposed to use fiber links instead of coaxial cables in aircraft specifically in Unmanned Air Vehicle. In this work, the advantages and limitations of these fiber links are discussed both for point to point and Wavelength Division Multiplexing based distribution architectures as a part of feasibility analysis for realization. The work includes the results of the analysis carried out for radio frequency as well as digital signals and weight analysis.