Coherent all-fibre optical beam-steering technique for phased-array antennas

A novel technique for coherent optical control of RF phase and frequency is presented. A central unit supplies one (fibre optic) output per antenna transmit/receive (T/R) element. Its overall efficiency is higher than in all known standard concepts for optical beam-forming. The effort for adjustment is low. External influences on the overall stability are low. The total mass is low compared with a solution with electronic components, as in almost all optical setups. This approach is suitable for continuous deflection of scanning of multiple (individually controllable) beams with multiple frequencies. The control of static phase and amplitude of each channel can be realised in the optical domain with moderate effort. Then the complexity of the T/R modules can be reduced on replacing these phase and amplitude controlling electronic components. Chirp generation, as used by SAR instruments, or information modulated RF signals are also achievable