Research On Key Technologies Of Microwave Photonic Multi-beam Forming

Microwave photonics is applied to the phased array antenna system to achieve wideband and wide angle applications,which solves the "beam tilt" effect of the phased array.In order to obtain a high-precision multi-beamforming system,an optical true-time delay(OTTD)technique is proposed,and the beam system T/R components are designed and manufactured The specific contents are as follows:1.Based on the phased array beamforming theory,the principle of optically controlled phased array beamforming is deduced,and a mathematical model is constructed.The phase-array "aperture effect" is eliminated by the OTTD technique,and simulation analysis are given.2.A design technical scheme is proposed for the beamforming system,and the fiber delay line and optical device control are proposed to realize the multi-beam system.A multi-beam network with optical switch and wavelength division multiplexer as technology is designed respectively.A multi-beam system with topological structure is proposed by combining two control technologies.An example of beam design for 32 fixed positions of the X-band antenna array in the ±60° range is given,and a simulation demonstration is given3.It is proposed to replace the single-mode fiber with a linear chirped fiber grating(LCFBG)to achieve continuous beam scanning and complete the optimization design.A LCFBG is designed for 5bit fiber grating delay network,and two optimization schemes are given.The delay range and scanning accuracy are obtained through simulation and modeling4.The T/R component of microwave photonic multi-beam forming system is designed and implemented,and an X-band T/R component suitable for the system is manufactured.Through the simulation analysis and physical testing,the design indicators of the system are satisfied.