非谐振单元加载的宽带超表面透镜天线设计

传统标准增益喇叭天线测试系统在测试物体的电磁特性时,由于要满足入射波为平面波的要求,通常要满足天线的远场条件,这样在测试过程中会产生绕射等现象,影响测试结果。通过在天线波导口处加载相位补偿的非谐振超表面单元可以改变电磁波的传播方向,使其在近场处也可以产生近似平面波的效果,可解决在测试过程中绕射等现象导致的测试结果不准确的问题。基于非谐振超表面单元,设计了一款工作在X波段的、由12×16个单元构成的二维透射型超表面,并将其加载在X波段标准增益的喇叭天线上,在不影响天线增益的情况下,将天线辐射出的球面波经过超表面的相位补偿后在近场形成近平面波。最后,通过仿真证明了该设计的正确性。

Design of broadband metasurface lens for Horn antenna using non-resonant unit

Traditional measurement system using standard Horn antenna requires plane wave for both the transmitter and the receiver,which can only be achieved meeting the far-field condition of each antennas.This brings much interference from diffraction,etc.By loading a phase-compensated non-resonant metasurface unit at the antenna waveguide port,the propagation direction of electromagnetic waves can be optimized to form a quasiplane wave.Based on a non-resonant metasurface element,a two-dimensional transmissive metasurface is designed composed of 12×16 elements in the X-band and loads it on a standard Horn antenna,while not affecting the antenna gain.After loading,the wave radiated by the antenna undergoes a phase compensation of the metasurface and forms a quasi-plane wave in the near field region.The design is validated through software simulation.