一种宽频带复合天线设计

Design of A Wideband Compound Antenna

针对多系统载体天线数量多的问题,提出了一种基于印刷振子结构的宽频带共口径复合天线设计方法;通过两种不同形式的印刷偶极子进行共口径设计:采用平面印刷偶极子结构完成宽带高增益线极化天线,通过宽带定向耦合器实现了天线和差方向图辐射;采用十字印刷偶极子实现低增益天线的圆极化辐射;两种天线单元印刷在同一微波介质上,通过优化天线单元布局,相对位置关系和增加金属隔离环等措施,降低天线之间的相互影响,实现共口径复合天线性能满足工程应用要求;加工了天线样机,测试结果表明线极化天线在工作频带1.2~1.8 GHz范围内和差通道电压驻波比小于1.8,和通道增益大于13.5 dBi,方位差波束零值深度小于-25 dB,圆极化天线在工作频带1.2~1.8 GHz范围内电压驻波比小于1.6,增益大于6.5 dBi,轴比小于2.5 dB,与计算结果基本一致;复合天线可以满足多种无线通信系统的需求,减少了天线数量,有效节省载体平台空间,同时具有结构简单紧凑、剖面低、易于工程实现等特点,具有广阔的应用前景。

To address the challenge of accommodating a large number of multi-system carrier antennas,a wideband shared aper-ture compound antenna based on printed dipole structure is proposed.The shared aperture design incorporates two distinct forms of printed dipoles.A planar printed dipole structure is used to achieve for the wideband high-gain linear polarization antenna,a wideband directional coupler for the sun-difference pattern radiation,and a cross dipole low-gain antenna for the circular polarization radiation.These antenna elements are printed on the same microwave dielectric substrate,and the mutual interference between them is mitigated through the techniques including the antenna unit layout optimization,relative positioning,and isolation rings.The performance of common aperture composite antennas is achieved to meet the needs of engineering application,and process an antenna prototype.The test results show that the VSWR is less than l.8,the gain is greater than 13.5 dBi,the azimuth difference beam zero depth is less than-25 dB of the linear polarized antenna in the range of 1.2~1.8 GHz;and the VSWR is less than 1.6,the gain is more than 6.5 dBi,the axial ratio is less than 2.5 dB of the circularly polarized antenna in the range of 1.2~1.8 GHz,the test results are basically consistent with the calculation results.The proposed design can meet the requirements of various wireless communication systems by reducing the number of antennas,thereby effectively saving space on the carrier platform.The compound antenna has broad applica-tion prospects,thanks to its simple and compact structure,low profile,and ease of engineering implementation.