Optically controlled phased-array antennas using chriped-fiber gratings

Abstract

A true-time beamformer based on a multichannel chriped fiber grating (MCFG) is capable of projecting free-squint beam operation and the benefits it possess have led to board applications especially in the field of optical beam-forming technology. The system generates time delay among its optical system to perform beam steering. However, optical signal often degrades along the system and the optical fiber. As such, a suggested topology is to include an erbium-doped fiber amplifier (EDFA) in the system to amplifier the signal strength. Next we have to consider the non-linear effects of the amplifier to ensure proper amplification is achievable. The non-linear effects of the EDFA can be investigated using the rate equations that characterize the behavior of the amplifier. And by reducing the rate equations to a simple ordinary differential equation (ODE), Simulink model can be adopted using the ODE to simulate the performance of the EDFA. Results have shown that the dynamics of the EDFA are dependent on the fiber profile. With appropriate compensation for the non-linearity of the fiber, signal losses to the beamforming system can be kept at minimum to avoid beam squint.