仿生复眼多级耦合光学天线优化设计及分析

Optimum Design and Analysis of Bionic Compound Eyes Multistage Coupling Optical Antenna

在阴影遮挡等非视距应用场景中,可见光通信系统的性能受限于严重的光功率衰减影响。基于仿生复眼的工作原理,设计了一种球面仿生复眼微透镜组和复合抛物面聚光器耦合的光学接收天线。利用Trace Pro软件分析球面仿生复眼的非成像特性,发现当探测面面积一定时,随着邻子眼光轴夹角减小,能量收集比率逐步提高,当邻子眼光轴夹角小于局部最优值时,能量收集比率达90%以上,接近最优。光轴夹角的局部最优值与探测器面积呈正相关。复眼的大视场特性随邻子眼光轴夹角的增大而逐步丧失,最终趋近于单透镜特性。对于可见光通信非视距链路的应用,可获得天线增益达56.45,视场角大于90°。利用MATLAB对室内信道进行数值分析,证明了仿生复眼多级耦合光学天线在阴影遮挡严重的场景下依旧能保持较高的馈入光功率,与普通的单透镜天线相比,平均功率提高了20 d Bm,表明所设计的光学天线具有大视场和高增益的特性,可有效提高室内可见光通信系统的抗阴影遮挡性能。

The performance of a visible optical communication system is limited by the effect of severe light power attenuation in application scenes of non-line-of-sight（ NLOS） propagation such as shadow occlusion,etc. Thus,we propose a kind of optical receiving antenna coupled with spherical bionic compound eye micro-lens group and a compound parabolic concentrator. By using Trace Pro to analyze the non-imaging characteristics of bionic compound eye of spherical surface,we find that the ratio of energy collection increases with the decrease of angle of the neighbor’s eye axis when the area of detection surface is certain. When the included angle between adjacent optical axes is less than local optimal value,the energy collection rate is more than 90%,which is close to the optimum. There is a positive correlation between the local optimal value of the angle of the optical axis and the area of the detector. With the increase of angle of the neighbor’s eye axis,the character of large field of vision（ FOV） of bionic compound eye is gone. For the application of NLOS linkof indoor visible light communication,the antenna gain can reach 56. 45 and the angle of FOV is larger than 90°.Compared with the ordinary single-lens antenna,it is clear that the bionic compound eye multilevel coupling optical antenna can maintain a high light feeding power in the case of severe shading,and the average power is increased by 20 dB m. It also shows that the design of the optical antenna with large FOV and high gain characteristics can effectively improve the anti-shadowing performance of indoor visible light communication system.