带宽极限下的宽带平面反射阵天线设计

摘要

Planar reflect-array is a two dimensional array consisting of metallic patches,which is illuminated by a primary feed horn.The spatial phase delay is compensated by the phase shift of the patch elements.The advantage of this antenna is that the main beam can be designed to tilt away from its broadside direction.But the significant defect is its narrow bandwidth,which is caused by the elements and the reflector’s operating principle.In this paper,the influence of the spatial phase delay on the antenna performance is dis⁃cussed,and then a new kind of element with linear phase shift over 500 degree is introduced.The reflect-array antenna comprising such elements acquires 25.3% 1 dB bandwidth,which has a significant improvement over the traditional structures.%平面反射阵是由金属贴片单元组成的二维阵列，一般用喇叭馈源进行馈电，通过谐振贴片单元的相移量补偿馈源到平面反射阵的空间相位延迟。平面反射阵天线的优势在于主波束指向灵活可控。但由于阵列单元自身的带宽限制和反射机理所致，其主要缺陷是工作带宽窄。在讨论空间相移对天线性能的影响的基础上，设计了一种相位线性变化达500°的新型反射阵单元。用该单元组阵的平面反射阵天线，其1 dB带宽达到25�3％，与传统平面阵结构的天线带宽相比，具有显著的改善。