倾斜波束圆极化天线的CSRR-FS结构设计研究

为了拓展倾斜波束圆极化天线(Circularly Polarized Antenna with Tilted Beam,CPA-TB)的带宽,在分析了该天线结构及其特征的基础上,提出了一种花纹式螺旋臂(Flower-Spiral,FS)协同互补开口谐振环(complementary split ring resontor,CSRR)的CSRR-FS结构.该结构通过FS增加了天线表面电流路径,实现了天线驻波比(voltage standing wave ratio,VSWR)的拓展;利用CSRR改变了低频点反射板的电流分布,实现反射板小型化的同时,减小了天线的交叉极化分量,增强了天线的辐射性能,拓展了天线的轴比带宽.仿真和实测结果表明:与普通的平面反射板相比,在保证圆极化、波束倾角30°的条件下,基于CSRR-FS结构的CPA-TB相对带宽为24%(5.5-7GHz),天线工作带宽拓展了1.8倍.CSRR-FS结构的提出为CPA-TB带宽的拓展提供了新的途径.

Research on CSRR-FS Structure of Circularly Polarized Antenna with Tilted Beam

Based on the analysis of the configuration and the character of the circularly polarized antenna with tilted beam, a novel CSRR-FS(Complementary Split Ring Resonator with Flower-Spiral, CSRR-FS)structure is proposed to increase the bandwidth of the antenna.This structure is designed through the flower-spiral arm and five complementary split ring resonator(CSRR)splits loaded on ground plane.The VSWR(voltage standing wave ratio)is enhanced through the flower-spiral structure.And respectively, five CSRR splits are loaded on the perfect electronic conductor ground plane to miniaturize the ground plane and decrease the cross-polarization component.The axial ratio is improved through the ground plane loaded five CSRR splits.Simulated and measured results both show that the relative bandwidth of the novel antenna with the CSRR-FS structure is 24% from 5.5GHz to 7GHz in the condition of circularly polarized radiation.And while, it is an azimuth angle of 30° tilted beam by the CSRR-FS structure.The bandwidth increases 1.8 times as wide as one without the CSRR-FS structure in the same condition.The proposed structure is an effectively method for increasing the bandwidth of circularly polarized antenna with tilted beam.