摘要:
基于小型化超构表面，设计了一款宽带基片集成波导 (substrate integrated waveguide, SIW)背腔缝隙天线。首先，在传统H型缝隙的基础上引入了新的谐振点，并通过引入由共面波导馈电网络激发的高阶谐振模式，进一步拓展了阻抗带宽，SIW缝隙天线的带宽可达到20.7% (12.1～14.9 GHz)；其次，为解决缝隙天线高频增益陡降问题，加载小型化超构表面，有效提升了增益稳定性。超构表面由4个顺序旋转的3×3超构单元组成，每个单元上蚀刻金属通孔实现超构表面的小型化。仿真和测试结果表明，所设计的天线阻抗带宽为27.6%(11.25～14.85 GHz)，峰值增益为9.4 dBi，其中高频段增益相比于未加载超构表面的SIW缝隙天线平均提升1.7 dBi，最大值为2.3 dBi。所设计的天线在通信领域具有良好的应用场景。
Abstract:
A broadband substrate integrated waveguide (SIW) back-cavity slit antenna is designed based on a miniaturized metasurface. Firstly, several new resonant points are introduced based on the traditional H-shape slot to improve the bandwidth. The higher-order resonant modes in the sub-cavity are excited by the ground-based coplanar waveguide feeding network. A wide impedance bandwidth can be achieved by introducing the higher-order modes closer. By this means, the final bandwidth of the slot antenna can reach 20.7% (12.1−14.9 GHz). Secondly, the antenna is further improved by loading the miniaturized metasurface to solve the gain degradation in the high-frequency part. The metasurface is composed of four sequentially rotated 3×3 meta units and a metal via is etched on each unit to achieve miniaturization. Simulation and measured results demonstrate that the impedance bandwidth of the proposed antenna is 27.6% (11.25−14.85 GHz), and the peak gain is 9.4 dBi, in which the high-frequency band gain is improved by 1.7 dBi on average, and 2.3 dBi on maximum, compared with that of the SIW slot antenna without the metasurface. The designed antenna has good application scenarios in the field of communication.