A metamaterial structure method (MSM) for horn antenna is presented to achieve the conversion from spherical waves to plane waves in horn antenna. The MSM is based on a finite embedded coordinate transformation (FECT). The spatial continuous distribution of electromagnetic parameter for metamaterial layer is deduced, and then spatial discretization for application is obtained. Then corresponding electric and magnetic resonance units are designed and arranged in horn antenna. The amplitude and phase distribution of the aperture is improved by using MSM, and the directivity of antenna is enhanced. Compared to the metamaterials with the zero index of refraction, the present metamaterial has little scatter reflection in the continuousness of dielectric medium, and the radiation efficiency of antenna is enhanced. Based on three-dimensional full wave simulation of the finite-element method, it is validated that the wave surface in horn antenna is changed, the gain of the pencil beam is raised by 9 dB, and the half-power angles of the H face and E face are reduced by 2. l°and 1.0°, respectively.%为使喇叭天线内部传导的球面波向平面波发生转变,提出一种高增益喇叭天线的超介质构建方法(MSM).MSM方法先采用有限嵌入式坐标变换将喇叭天线内空气介质的电磁参数进行变换,得到一组在原空气介质所占空间内连续变化的电磁参数,再将连续的电磁参数在空间离散化,并设计对应的电谐振和磁谐振单元,最后排布谐振单元实现超介质的构建.在喇叭天线中应用该超介质,改善了口面场的幅相分布,提高了喇叭天线主瓣的方向系数.与零折射率超介质构建方法相比,MSM方法消除了电磁波在介质分界面上的反射,提高了喇叭天线的辐射效率.采用基于有限元算法的COMSOL软件对电磁波在喇叭天线内的传导特性及增益方向图进行三维数值模拟,并与常规喇叭天线进行对比,结果表明:喇叭天线过渡段内波面形式发生了转变,主瓣增益提高了9dB,主H面和主E面的半功率角分别减小了2.1°和1.0°.
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