基于LC耦合机制调谐设计薄屏宽带频率选择表面

以环形单元为基础设计出一种三屏金属阵列通过两层薄介质级联的频率选择表面(FSS)。建立等效电路模型,根据传输线理论给出金属栅格阵列(感性表面)与间隔的金属方环(容性表面)的近似电容、电感公式,通过调整结构几何参数分析LC 耦合机制,调谐出最优的宽带传输特性。最后,采用PCB 加工工艺制备了FSS 样件并在暗室进行了传输特性测试。得到的测试结果与数值结果一致,结果表明这种频率选择表面对电磁波大角度入射和不同电磁波极化方式都具有稳定的传输特性。

Design Broadband-Pass Frequency Selective Surface Utilizing a Thin Substrate Based on LC Couplings

In this letter, we propose a frequency selective surface (FSS) made of three metal layers cascade by two layers substrates. An equivalent circuit model for the operating principle of FSS was proposed. On the basis of the transmission lines theory, the approximation formulas of the inductance and capacitance were provided. In order to the optimal parameters of broadband performance, the impact of geometrical parameters on LC coupling is discussed by the analysis of simulation calculated. A prototype was fabricated and a measured. A good agreement between the simulated and measured transmission coefficients is obtained. Furthermore, The FSS under the oblique incidence and different polarizations also present stabilized wideband band-pass performances.